Timer processing method and terminal device

ABSTRACT

A timer processing method includes: receiving, by a terminal device, a first message sent by a network device, and starting or restarting a timer based on a scrambling identifier of the first message, wherein the timer is a timer used by the terminal device to switch from an active downlink BWP to a default downlink BWP, or is a timer used by the terminal device to activate a default downlink BWP and deactivate an active downlink BWP; or if an active BWP pair of the terminal device is not a default BWP pair, starting or restarting, by the terminal device, a timer based on a scrambling identifier of the first message, wherein the timer is a timer used by the terminal device to switch from the active BWP pair to the default BWP pair, or is a timer used by the terminal device to activate the default BWP pair.

TECHNICAL FIELD

This application relates to communications technologies, and inparticular, to a timer processing method and a terminal device.

BACKGROUND

As communications technologies continuously develop, a 5th generation(5th-Generation, 5G) new radio (New Radio, NR) technology introduces aconcept of bandwidth part (Bandwidth Part, BWP). In the first release of5G NR, namely, in the 5G NR Rel-15, a base station can configure amaximum of 4 BWPs on one bandwidth carrier for one terminal device. Oneterminal device has only one active downlink BWP and one active uplinkBWP in one serving cell at any moment. In a paired spectrum scenario,namely, with frequency division duplexing (Frequency Division Duplexing,FDD), the configured BWPs may include one default downlink BWP (defaultDL BWP), and if no default downlink BWP is configured, an initial DL BWP(initial DL BWP) is the default downlink BWP by default. In an unpairedspectrum scenario, namely, with Time Division Duplexing (Time DivisionDuplexing, TDD), an uplink BWP and a downlink BWP appear in pairs, andthe paired uplink BWP and downlink BWP are referred to as anuplink/downlink BWP (DL/UL BWP) pair or a BWP pair. The configured BWPsmay include one default BWP pair (default BWP pair), and if no defaultBWP pair is configured, an initial BWP pair (initial BWP pair) is thedefault BWP pair by default. The default BWP corresponds to relativelynarrow downlink bandwidth. A terminal device working on the defaultdownlink BWP needs to listen to downlink control information (DownlinkControl Information, DCI) on a narrow band only. The downlink controlinformation is carried on a physical downlink control channel (PhysicalDownlink Control Channel, PDCCH), that is, the downlink controlinformation is sent on the PDCCH. In other words, blind detection isperformed in relatively small search space. Therefore, power consumptionof the terminal device can be reduced. It should be noted that,receiving a PDCCH by a terminal device may be understood as receivinginformation carried on the PDCCH, or understood as receiving informationsuch as DCI sent on the PDCCH.

A concept of BWP timer is introduced to reduce power consumption of userequipment. A BWP inactivity timer is used as an example. The BWPinactivity timer is a timer that controls the terminal device to fallback to a default downlink BWP or a default BWP pair. In the pairedspectrum scenario, when the terminal device works on an active downlinkBWP, and the active downlink BWP is not the default downlink BWP, theterminal device needs to run the BWP inactivity timer. In the unpairedspectrum scenario, when the terminal device works on an active BWP pair,and the active BWP pair is not the default BWP pair, the terminal deviceneeds to run the BWP inactivity timer. When the BWP inactivity timerexpires, it indicates that the terminal device does not receive adownlink assignment in a specific period of time. In this case, theterminal device does not need to work on large bandwidth for datacommunication and only needs to work on narrow bandwidth. In otherwords, the terminal device may automatically switch to and work on thedefault downlink BWP or the default BWP pair, to reduce the powerconsumption of the terminal device.

In the prior art, whether to start a BWP inactivity timer is determinedbased on a PDCCH that is received by a terminal device and thatindicates a downlink assignment (downlink assignment), or is determinedbased on a PDCCH that is received by a terminal device and thatindicates switching to a non-default BWP. A default BWP may beunderstood as a default downlink BWP or a default BWP pair. To bespecific, the BWP inactivity timer is started or restarted provided thatthe terminal device receives the PDCCH indicating a downlink assignmentor indicating switching to a non-default BWP. It should be noted that,BWP switching may be understood as activating one inactive BWP anddeactivating one active BWP. BWP switching may be downlink BWP switchingor BWP pair switching. The BWP pair switching may be understood asswitching both a downlink BWP and an uplink BWP. However, in the priorart, there is an error or an omission during timer start or restart.Consequently, the terminal device cannot correctly switch to a defaultdownlink BWP, and power consumption of the terminal device cannot bereduced.

SUMMARY

This application provides a timer processing method and a terminaldevice, to resolve a prior-art problem that a terminal device cannotcorrectly switch to a default downlink BWP and power consumption of theterminal device cannot be reduced because there is an error or anomission during timer start or restart.

According to a first aspect, an embodiment of this application providesa timer processing method. The timer processing method may include:

receiving, by a terminal device, a first message sent by a networkdevice, wherein the first message is used to indicate a downlinkassignment or an uplink grant, or the first message is used to indicatebandwidth part BWP switching; and

if an active downlink BWP of the terminal device is not a defaultdownlink BWP, starting or restarting, by the terminal device, a timerbased on a scrambling identifier of the first message, wherein the timeris a timer used by the terminal device to switch from the activedownlink BWP to the default downlink BWP, or the timer is a timer usedby the terminal device to activate the default downlink BWP anddeactivate the active downlink BWP; or

if an active BWP pair of the terminal device is not a default BWP pair,starting or restarting, by the terminal device, a timer based on ascrambling identifier of the first message, wherein the timer is a timerused by the terminal device to switch from the active BWP pair to thedefault BWP pair, or the timer is a timer used by the terminal device toactivate the default BWP pair and deactivate the active BWP pair.

It can be learned that, different from the prior art in which a timer isdirectly started or restarted after a PDCCH is directly received, inthis embodiment of this application, in determining of whether to startor restart a timer, whether to start or restart a timer further needs tobe determined based on the scrambling identifier of the first messageafter the first message is received. This resolves a problem that theterminal device cannot correctly switch to the default downlink BWP andpower consumption of the terminal device cannot be reduced, therebyreducing the power consumption of the terminal device.

In a possible implementation, the starting or restarting, by theterminal device, a timer based on a scrambling identifier of the firstmessage includes:

starting or restarting, by the terminal device, the timer when thescrambling identifier is not a random access radio network temporaryidentifier RA-RNTI or a temporary cell radio network temporaryidentifier TC-RNTI.

In a possible implementation, the starting or restarting, by theterminal device, a timer based on a scrambling identifier of the firstmessage includes:

starting or restarting, by the terminal device, the timer when thescrambling identifier is a first scrambling identifier, wherein thefirst scrambling identifier is any one or a combination of a cell radionetwork temporary identifier C-RNTI, a configured scheduling radionetwork temporary identifier CS-RNTI, a paging radio network temporaryidentifier P-RNTI, and a system information radio network temporaryidentifier SI-RNTI.

In a possible implementation, the starting or restarting, by theterminal device, a timer based on a scrambling identifier of the firstmessage includes:

starting or restarting, by the terminal device, the timer when thescrambling identifier is a random access radio network temporaryidentifier RA-RNTI and the terminal device executes non-contention-basedrandom access.

In a possible implementation, the timer processing method may furtherinclude:

when the scrambling identifier is an RA-RNTI and the terminal deviceexecutes contention-based random access, controlling, by the terminaldevice, the timer to maintain an original state.

In a possible implementation, the timer is a timer associated with theactive downlink BWP of the terminal device, or the timer is a timerassociated with the active BWP pair of the terminal device.

According to a second aspect, an embodiment of this application furtherprovides a timer processing method. The timer processing method mayinclude:

receiving, by a terminal device, a first message sent by a networkdevice, wherein the first message is used to indicate a downlinkassignment or an uplink grant, or the first message is used to indicatebandwidth part BWP switching; and

starting or restarting, by the terminal device, a timer based on acarrier index of the first message, wherein the timer is a timer used bythe terminal device to switch from an active downlink BWP to a defaultdownlink BWP, or the timer is a timer used by the terminal device toactivate a default downlink BWP and deactivate an active downlink BWP,or the timer is a timer used by the terminal device to switch from anactive BWP pair to a default BWP pair, or the timer is a timer used bythe terminal device to activate a default BWP pair and deactivate anactive BWP pair.

It can be learned that, different from the prior art in which a timer isdirectly started or restarted after a PDCCH is directly received, inthis embodiment of this application, in determining of whether to startor restart a timer, whether to start or restart a timer further needs tobe determined based on a carrier identifier of the first message afterthe first message is received. This resolves a problem that the terminaldevice cannot correctly switch to the default downlink BWP and powerconsumption of the terminal device cannot be reduced, thereby reducingthe power consumption of the terminal device.

In a possible implementation, if the active downlink BWP of the terminaldevice is not the default downlink BWP and the active downlink BWP ofthe terminal device is a downlink BWP of a carrier or a serving cellindicated by the carrier index, or if the active BWP pair of theterminal device is not the default BWP pair and the active BWP pair ofthe terminal device is a BWP pair of a carrier or a serving cellindicated by the carrier index, the timer is a timer of the carrier orthe serving cell.

In a possible implementation, if the active downlink BWP of the terminaldevice is not the default downlink BWP and the active downlink BWP ofthe terminal device is a downlink BWP of a carrier or a serving cellused for receiving the first message, or if the active BWP pair of theterminal device is not the default BWP pair and the active BWP pair ofthe terminal device is a BWP pair of a carrier or a serving cell usedfor receiving the first message, the timer is a timer of the carrier orthe serving cell used for receiving the first message.

In a possible implementation, the timer is a timer associated with theactive downlink BWP of the terminal device, or the timer is a timerassociated with an active downlink BWP of the terminal device on thecarrier or in the serving cell, or the timer is a timer associated withthe active BWP pair of the terminal device, or the timer is a timerassociated with an active BWP pair of the terminal device on the carrieror in the serving cell.

According to a third aspect, an embodiment of this application furtherprovides a timer processing method. The timer processing method mayinclude:

determining, by a terminal device, that at least one configured resourceexists; and

if an active bandwidth part BWP pair of the terminal device is not adefault BWP pair, starting or restarting, by the terminal device, atimer based on the at least one configured resource that exists, whereinthe timer is a timer used by the terminal device to switch from theactive BWP pair to the default BWP pair, or the timer is a timer used bythe terminal device to activate the default BWP pair and deactivate theactive BWP pair.

It can be learned that, in this embodiment of this application, withsemi-dynamic scheduling, when at least one configured resource exists,whether to start or restart a timer may be determined based on the atleast one configured resource that exists. This resolves a problem thatthe terminal device cannot correctly switch to the default downlink BWPand power consumption of the terminal device cannot be reduced, therebyreducing the power consumption of the terminal device.

In a possible implementation, data is transmitted on the configuredresource.

In a possible implementation, the starting or restarting, by theterminal device, a timer based on the at least one configured resourcethat exists includes:

the configured resource is a downlink resource or an uplink resource;and

starting or restarting, by the terminal device, the timer whendetermining that the at least one configured resource exists; orstarting or restarting, by the terminal device, the timer when theconfigured resource is a downlink resource and downlink data istransmitted on the downlink resource; or starting or restarting, by theterminal device, the timer when the configured resource is an uplinkresource and uplink data is transmitted on the uplink resource.

In a possible implementation, the timer is a timer associated with theactive BWP pair of the terminal device.

In addition, it should be noted that, when a timer is associated with aBWP, the timer processing method may further be a method illustrated inany one of the following fourth to sixth aspects.

According to the fourth aspect, an embodiment of this applicationprovides a timer processing method. The method may include:

receiving, by a terminal device, an instruction message sent by anetwork device, wherein the instruction message instructs the terminaldevice to activate at least one secondary serving cell; and

starting or restarting, by the terminal device, a timer associated withthe secondary serving cell, wherein the timer is a timer used by theterminal device to switch from an active downlink bandwidth part BWP toa default downlink BWP, or the timer is a timer used by the terminaldevice to activate a default downlink BWP and deactivate an activedownlink BWP, or the timer is a timer used by the terminal device toswitch from an active BWP pair to a default BWP pair, or the timer is atimer used by the terminal device to activate a default BWP pair anddeactivate an active BWP pair.

In a possible implementation, the secondary serving cell is in aninactive state.

In a possible implementation, before the receiving, by a terminaldevice, an instruction message sent by a network device, the method mayfurther include:

receiving, by the terminal device, a radio resource control RRC messagesent by the network device, wherein the RRC message includes instructioninformation, wherein the instruction information instructs to add ormodify the at least one secondary serving cell, the RRC message furtherincludes a first downlink BWP of the secondary serving cell, the firstdownlink BWP is a downlink BWP that is first activated when thesecondary serving cell is activated, and the first downlink BWP is not adefault downlink BWP; or the RRC message further includes a first BWPpair of the secondary serving cell, the first BWP pair is a BWP pairthat is first activated when the secondary serving cell is activated,and the first BWP pair is not a default downlink BWP pair.

In a possible implementation, the timer is a timer associated with thefirst downlink BWP, or the timer associated with the secondary servingcell is a timer associated with a first downlink BWP of the terminaldevice in the secondary serving cell, or the timer is a timer associatedwith the first BWP pair, or the timer associated with the secondaryserving cell is a timer associated with a first BWP pair of the terminaldevice in the secondary serving cell; and

the starting or restarting, by the terminal device, a timer associatedwith the secondary serving cell includes:

starting or restarting, by the terminal device, the timer associatedwith the first downlink BWP of the secondary serving cell, or startingor restarting, by the terminal device, the timer associated with thefirst BWP pair of the secondary serving cell.

According to the fifth aspect, an embodiment of this applicationprovides a timer processing method. The method may include:

receiving, by a terminal device, an instruction message sent by anetwork device, wherein the instruction message instructs the terminaldevice to deactivate at least one secondary serving cell, and a timerassociated with the secondary serving cell is in a running state,wherein the timer is a timer used by the terminal device to switch froman active downlink bandwidth part BWP to a default downlink BWP, or thetimer is a timer used by the terminal device to activate a defaultdownlink BWP and deactivate an active downlink BWP, or the timer is atimer used by the terminal device to switch from an active BWP pair to adefault BWP pair, or the timer is a timer used by the terminal device toactivate a default BWP pair and deactivate an active BWP pair; and

stopping or resetting, by the terminal device, the timer associated withthe secondary serving cell, or stopping and resetting, by the terminaldevice, the timer associated with the secondary serving cell.

In a possible implementation, the timer is a timer associated with theactive downlink BWP of the terminal device, or the timer associated withthe secondary serving cell is a timer associated with an active downlinkBWP of the terminal device in the secondary serving cell, or the timeris a timer associated with the active BWP pair of the terminal device,or the timer associated with the secondary serving cell is a timerassociated with an active BWP pair of the terminal device in thesecondary serving cell.

According to the sixth aspect, an embodiment of this applicationprovides a timer processing method. The method may include:

determining, by a terminal device, that a secondary serving celldeactivation timer of a secondary serving cell expires, wherein a timerassociated with the secondary serving cell is in a running state,wherein the timer is a timer used by the terminal device to switch froman active downlink bandwidth part BWP to a default downlink BWP, or thetimer is a timer used by the terminal device to activate a defaultdownlink BWP and deactivate an active downlink BWP, or the timer is atimer used by the terminal device to switch from an active BWP pair to adefault BWP pair, or the timer is a timer used by the terminal device toactivate a default BWP pair and deactivate an active BWP pair; and

stopping or resetting, by the terminal device, the timer associated withthe secondary serving cell, or stopping and resetting, by the terminaldevice, the timer associated with the secondary serving cell.

In a possible implementation, the timer is a timer associated with theactive downlink BWP of the terminal device, or the timer associated withthe secondary serving cell is a timer associated with an active downlinkBWP of the terminal device in the secondary serving cell, or the timeris a timer associated with the active BWP pair of the terminal device,or the timer associated with the secondary serving cell is a timerassociated with an active BWP pair of the terminal device in thesecondary serving cell.

It should be noted that, in the timer processing method illustrated inany one of the fifth and the sixth aspects, the timer associated withthe secondary serving cell may be a timer associated with any one or allof active BWPs of the secondary serving cell.

According to a seventh aspect, an embodiment of this application furtherprovides a terminal device. The terminal device may include:

a receiving unit, configured to receive a first message sent by anetwork device, wherein the first message is used to indicate a downlinkassignment or an uplink grant, or the first message is used to indicatebandwidth part BWP switching; and

a processing unit, configured to: if an active downlink BWP of theterminal device is not a default downlink BWP, start or restart a timerbased on a scrambling identifier of the first message, wherein the timeris a timer used by the terminal device to switch from the activedownlink BWP to the default downlink BWP, or the timer is a timer usedby the terminal device to activate the default downlink BWP anddeactivate the active downlink BWP; wherein

the processing unit is further configured to: if an active BWP pair ofthe terminal device is not a default BWP pair, start or restart a timerbased on the scrambling identifier of the first message, wherein thetimer is a timer used by the terminal device to switch from the activeBWP pair to the default BWP pair, or the timer is a timer used by theterminal device to activate the default BWP pair and deactivate theactive BWP pair.

In a possible implementation, the processing unit is specificallyconfigured to start or restart the timer when the scrambling identifieris not a random access radio network temporary identifier RA-RNTI or atemporary cell radio network temporary identifier TC-RNTI.

In a possible implementation, the processing unit is specificallyconfigured to start or restart the timer when the scrambling identifieris a first scrambling identifier, wherein the first scramblingidentifier is any one or a combination of a cell radio network temporaryidentifier C-RNTI, a configured scheduling radio network temporaryidentifier CS-RNTI, a paging radio network temporary identifier P-RNTI,and a system information radio network temporary identifier SI-RNTI.

In a possible implementation, the processing unit is specificallyconfigured to start or restart the timer when the scrambling identifieris a random access radio network temporary identifier RA-RNTI and theterminal device executes non-contention-based random access.

In a possible implementation, the terminal device may further include:

a maintaining unit, configured to, when the scrambling identifier is anRA-RNTI and the terminal device executes contention-based random access,control the timer to maintain an original state.

In a possible implementation, the timer is a timer associated with theactive downlink BWP of the terminal device, or the timer is a timerassociated with the active BWP pair of the terminal device.

According to an eighth aspect, an embodiment of this application furtherprovides a terminal device. The terminal device may include:

a receiving unit, configured to receive a first message sent by anetwork device, wherein the first message is used to indicate a downlinkassignment or an uplink grant, or the first message is used to indicatebandwidth part BWP switching; and

a processing unit, configured to start or restart a timer based on acarrier index of the first message, wherein the timer is a timer used bythe terminal device to switch from an active downlink BWP to a defaultdownlink BWP, or the timer is a timer used by the terminal device toactivate a default downlink BWP and deactivate an active downlink BWP,or the timer is a timer used by the terminal device to switch from anactive BWP pair to a default BWP pair, or the timer is a timer used bythe terminal device to activate a default BWP pair and deactivate anactive BWP pair.

In a possible implementation, if the active downlink BWP of the terminaldevice is not the default downlink BWP and the active downlink BWP ofthe terminal device is a downlink BWP of a carrier or a serving cellindicated by the carrier index, or if the active BWP pair of theterminal device is not the default BWP pair and the active BWP pair ofthe terminal device is a BWP pair of a carrier or a serving cellindicated by the carrier index, the timer is a timer of the carrier orthe serving cell.

In a possible implementation, if the active downlink BWP of the terminaldevice is not the default downlink BWP and the active downlink BWP ofthe terminal device is a downlink BWP of a carrier or a serving cellused for receiving the first message, or if the active BWP pair of theterminal device is not the default BWP pair and the active BWP pair ofthe terminal device is a BWP pair of a carrier or a serving cell usedfor receiving the first message, the timer is a timer of the carrier orthe serving cell used for receiving the first message.

In a possible implementation, the timer is a timer associated with theactive downlink BWP of the terminal device, or the timer is a timerassociated with an active downlink BWP of the terminal device on thecarrier or in the serving cell, or the timer is a timer associated withthe active BWP pair of the terminal device, or the timer is a timerassociated with an active BWP pair of the terminal device on the carrieror in the serving cell.

According to a ninth aspect, an embodiment of this application furtherprovides a terminal device. The terminal device may include:

a determining unit, configured to determine that at least one configuredresource exists; and

a processing unit, configured to: if an active bandwidth part BWP pairof the terminal device is not a default BWP pair, start or restart atimer based on the at least one configured resource that exists, whereinthe timer is a timer used by the terminal device to switch from theactive BWP pair to the default BWP pair, or the timer is a timer used bythe terminal device to activate the default BWP pair and deactivate theactive BWP pair.

In a possible implementation, data is transmitted on the configuredresource.

In a possible implementation, the configured resource is a downlinkresource or an uplink resource; and

the processing unit is specifically configured to: start or restart thetimer when the at least one configured resource exists; or start orrestart the timer when the configured resource is a downlink resourceand downlink data is transmitted on the downlink resource; or start orrestart the timer when the configured resource is an uplink resource anduplink data is transmitted on the uplink resource.

In a possible implementation, the timer is a timer associated with theactive BWP pair of the terminal device.

According to a tenth aspect, an embodiment of this application furtherprovides a terminal device. The terminal device may include a processorand a memory, wherein

the memory is configured to store a program instruction; and

the processor is configured to invoke and execute the programinstruction stored in the memory, to execute the timer processing methodaccording to any one of the first aspect to the third aspect.

According to a eleventh aspect, an embodiment of this applicationfurther provides a terminal device. The terminal device may include areceiver and a processor, wherein

the receiver is configured to receive a first message sent by a networkdevice, wherein the first message is used to indicate a downlinkassignment or an uplink grant, or the first message is used to indicatebandwidth part BWP switching; and

the processor is configured to: if an active downlink BWP of theterminal device is not a default downlink BWP, start or restart a timerbased on a scrambling identifier of the first message, wherein the timeris a timer used by the terminal device to switch from the activedownlink BWP to the default downlink BWP, or the timer is a timer usedby the terminal device to activate the default downlink BWP anddeactivate the active downlink BWP; or

the processor is configured to: if an active BWP pair of the terminaldevice is not a default BWP pair, start or restart a timer based on ascrambling identifier of the first message, wherein the timer is a timerused by the terminal device to switch from the active BWP pair to thedefault BWP pair, or the timer is a timer used by the terminal device toactivate the default BWP pair and deactivate the active BWP pair.

In a possible implementation, the processor is specifically configuredto start or restart the timer when the scrambling identifier is not arandom access radio network temporary identifier RA-RNTI or a temporarycell radio network temporary identifier TC-RNTI.

In a possible implementation, the processor is specifically configuredto start or restart the timer when the scrambling identifier is a firstscrambling identifier, wherein the first scrambling identifier is anyone or a combination of a cell radio network temporary identifierC-RNTI, a configured scheduling radio network temporary identifierCS-RNTI, a paging radio network temporary identifier P-RNTI, and asystem information radio network temporary identifier SI-RNTI.

In a possible implementation, the processor is specifically configuredto start or restart the timer when the scrambling identifier is a randomaccess radio network temporary identifier RA-RNTI and the terminaldevice executes non-contention-based random access.

In a possible implementation, the processor is further configured to,when the scrambling identifier is an RA-RNTI and the terminal deviceexecutes contention-based random access, control the timer to maintainan original state.

In a possible implementation, the timer is a timer associated with theactive downlink BWP of the terminal device, or the timer is a timerassociated with the active BWP pair of the terminal device.

According to an twelfth aspect, an embodiment of this applicationfurther provides a terminal device. The terminal device may include areceiver and a processor, wherein

the receiver is configured to receive a first message sent by a networkdevice, wherein the first message is used to indicate a downlinkassignment or an uplink grant, or the first message is used to indicatebandwidth part BWP switching; and

the processor is configured to start or restart a timer based on acarrier index of the first message, wherein the timer is a timer used bythe terminal device to switch from an active downlink BWP to a defaultdownlink BWP, or the timer is a timer used by the terminal device toactivate a default downlink BWP and deactivate an active downlink BWP,or the timer is a timer used by the terminal device to switch from anactive BWP pair to a default BWP pair, or the timer is a timer used bythe terminal device to activate a default BWP pair and deactivate anactive BWP pair.

In a possible implementation, if the active downlink BWP of the terminaldevice is not the default downlink BWP and the active downlink BWP ofthe terminal device is a downlink BWP of a carrier or a serving cellindicated by the carrier index, or if the active BWP pair of theterminal device is not the default BWP pair and the active BWP pair ofthe terminal device is a BWP pair of a carrier or a serving cellindicated by the carrier index, the timer is a timer of the carrier orthe serving cell.

In a possible implementation, if the active downlink BWP of the terminaldevice is not the default downlink BWP and the active downlink BWP ofthe terminal device is a downlink BWP of a carrier or a serving cellused for receiving the first message, or if the active BWP pair of theterminal device is not the default BWP pair and the active BWP pair ofthe terminal device is a BWP pair of a carrier or a serving cell usedfor receiving the first message, the timer is a timer of the carrier orthe serving cell used for receiving the first message.

In a possible implementation, the timer is a timer associated with theactive downlink BWP of the terminal device, or the timer is a timerassociated with an active downlink BWP of the terminal device on thecarrier or in the serving cell, or the timer is a timer associated withthe active BWP pair of the terminal device, or the timer is a timerassociated with an active BWP pair of the terminal device on the carrieror in the serving cell.

According to a thirteenth aspect, an embodiment of this applicationfurther provides a terminal device. The terminal device may include aprocessor, wherein

the processor is configured to determine that at least one configuredresource exists; and

the processor is configured to: if an active bandwidth part BWP pair ofthe terminal device is not a default BWP pair, start or restart a timerbased on the at least one configured resource that exists, wherein thetimer is a timer used by the terminal device to switch from the activeBWP pair to the default BWP pair, or the timer is a timer used by theterminal device to activate the default BWP pair and deactivate theactive BWP pair.

In a possible implementation, data is transmitted on the configuredresource.

In a possible implementation, the configured resource is a downlinkresource or an uplink resource; and

the processor is specifically configured to: start or restart the timerwhen determining that the at least one configured resource exists; orstart or restart the timer when the configured resource is a downlinkresource and downlink data is transmitted on the downlink resource; orstart or restart the timer when the configured resource is an uplinkresource and uplink data is transmitted on the uplink resource.

In a possible implementation, the timer is a timer associated with theactive BWP pair of the terminal device.

According to a fourteenth aspect, an embodiment of this applicationfurther provides a terminal device. The terminal device may include aprocessor and a memory, wherein

the memory is configured to store a program instruction; and

the processor is configured to invoke and execute the programinstruction stored in the memory, to execute the timer processing methodaccording to any one of the first aspect to the third aspect.

According to a fifteenth aspect, an embodiment of this applicationfurther provides a computer-readable storage medium, wherein

the computer-readable storage medium stores a computer program, and whenexecuted by a processor, the computer program executes the timerprocessing method according to any one of the first aspect to the thirdaspect.

According to a sixteenth aspect, an embodiment of this applicationfurther provides a chip, wherein the chip stores a computer program, andwhen executed by a processor, the computer program executes the timerprocessing method according to any one of the first aspect to the thirdaspect.

According to the timer processing method and the terminal deviceprovided in the embodiments of this application, in determining ofwhether to start or restart a timer, the terminal device receives thefirst message sent by the network device. If the active downlinkbandwidth part BWP of the terminal device is not the default downlinkBWP, the terminal device starts or restarts a timer based on thescrambling identifier of the first message, wherein the timer is a timerused by the terminal device to switch from the active downlink BWP tothe default downlink BWP, or the timer is a timer used by the terminaldevice to activate the default downlink BWP and deactivate the activedownlink BWP. If the active BWP pair of the terminal device is not thedefault BWP pair, the terminal device starts or restarts a timer basedon the scrambling identifier of the first message, wherein the timer isa timer used by the terminal device to switch from the active BWP pairto the default BWP pair, or the timer is a timer used by the terminaldevice to activate the default BWP pair and deactivate the active BWPpair. This resolves a problem that the terminal device cannot correctlyswitch to the default downlink BWP and power consumption of the terminaldevice cannot be reduced, thereby reducing the power consumption of theterminal device.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic diagram of an application scenario according to anembodiment of this application;

FIG. 2 is a schematic diagram of a timer processing method according toan embodiment of this application;

FIG. 3 is a schematic diagram of another timer processing methodaccording to an embodiment of this application;

FIG. 4 is a schematic diagram of another timer processing methodaccording to an embodiment of this application;

FIG. 5 is a schematic diagram of another timer processing methodaccording to an embodiment of this application;

FIG. 6 is a schematic diagram of another timer processing methodaccording to an embodiment of this application;

FIG. 7 is a schematic diagram of another timer processing methodaccording to an embodiment of this application;

FIG. 8 is a schematic structural diagram of a terminal device accordingto an embodiment of this application;

FIG. 9 is a schematic structural diagram of another terminal deviceaccording to an embodiment of this application;

FIG. 10 is a schematic structural diagram of another terminal deviceaccording to an embodiment of this application;

FIG. 11 is a schematic structural diagram of a terminal device accordingto an embodiment of this application;

FIG. 12 is a schematic structural diagram of another terminal deviceaccording to an embodiment of the present invention;

FIG. 13 is a schematic structural diagram of another terminal deviceaccording to an embodiment of this application; and

FIG. 14 is a schematic structural diagram of another terminal deviceaccording to an embodiment of this application.

DESCRIPTION OF EMBODIMENTS

The embodiments of this application are applied to a 5G communicationssystem or another system that may emerge in the future. The followingdescribes some terms used in this application, to facilitateunderstanding of a person skilled in the art. It should be noted that,when solutions in the embodiments of this application are applied to the5G communications system or the another system that may emerge in thefuture, names of a network device and a terminal may change, but thisdoes not affect implementation of the solutions in the embodiments ofthis application.

FIG. 1 is a schematic diagram of an application scenario according to anembodiment of this application. A networking architecture shown in FIG.1 mainly includes a network device 10 and a terminal device 20. Theterminal device may communicate with the network device. In thisapplication, the network device may configure both at least one downlinkBWP and at least one uplink BWP for one terminal device. In a pairedspectrum scenario, the at least one downlink BWP includes one defaultdownlink BWP. In an unpaired spectrum scenario, the at least onedownlink BWP includes one default downlink BWP, the at least one uplinkBWP includes one default uplink BWP, and the default downlink BWP andthe default uplink BWP are paired to form one default BWP pair. Thedefault downlink BWP corresponds to relatively narrow downlinkbandwidth. Therefore, when the terminal device transmits data on thedefault downlink BWP, the terminal device only needs to listen todownlink control information on a narrow band and perform blinddetection in relatively small search space, thereby reducing powerconsumption of the terminal device.

(1) A terminal device is also referred to as a terminal or userequipment, and is a device that provides voice and/or data connectivityfor a user, for example, a handheld device with a wireless connectionfunction or an in-vehicle device. For example, common terminal devicesinclude a mobile phone, a tablet computer, a notebook computer, apalmtop computer, a mobile internet device (mobile internet device,MID), and a wearable device. For example, wearable devices include asmartwatch, a smart band, and a pedometer.

(2) A network device is also referred to as a radio access network(Radio Access Network, RAN) device, and is a device that connects aterminal device to a wireless network. The network device includesnetwork devices of various communications standards, for example,including but not limited to a base station, an evolved NodeB (evolvedNode B, eNB), a radio network controller (radio network controller,RNC), a NodeB (Node B, NB), a base station controller (Base StationController, BSC), a base transceiver station (Base Transceiver Station,BTS), a home network device (for example, a home evolved NodeB, or ahome Node B, HNB), and a base band unit (Base Band Unit, BBU).

(3) Bandwidth part (band width part, BWP): When bandwidth of a cell islarge, a terminal device may work only on a part of the bandwidth of thecell. Each part of the bandwidth of the cell is referred to as a BWP.

(4) A network device includes network devices of various frequencystandards, for example, including but not limited to a low-frequencynetwork device and a high-frequency network device.

(5) “A plurality of” means two or more, and another quantifier issimilar to this. The term “and/or” describes an association relationshipfor describing associated objects and represents that threerelationships may exist. For example, A and/or B may represent thefollowing three cases: Only A exists, both A and B exist, and only Bexists. The character “/” generally indicates an “or” relationshipbetween the associated objects.

In the prior art, whether a BWP inactivity timer is started isdetermined based on a PDCCH received by a terminal. To be specific, theBWP inactivity timer is started or restarted provided that the PDCCHreceived by the terminal indicates a downlink assignment or indicatesswitching to a non-default BWP. However, in the prior art, there is anerror or an omission during timer start or restart, and consequently theterminal cannot correctly switch to a default downlink BWP and powerconsumption of the terminal cannot be reduced. To resolve the problem inthe prior art, an embodiment of this application provides a timerprocessing method, in which a terminal device does not directly start orrestart a timer after receiving a first message sent by a networkdevice, but needs to determine a scrambling identifier of the firstmessage or a carrier index of the first message, to further determinewhether to start or restart the timer. In addition, this embodiment ofthis application further provides a method for starting or restarting,in a non-dynamic scheduling scenario, a timer based on at least oneconfigured resource that exists. This resolves the prior-art problemthat a terminal device cannot correctly switch to a default downlink BWPand power consumption of the terminal cannot be reduced.

It should be noted that, when a timer is started or restarted in theforegoing three manners, the timer may be a timer associated with aserving cell or a timer associated with a BWP. In the first release of5G NR, on a first bandwidth carrier, one terminal device has only oneactive downlink BWP or uplink BWP in a serving cell at any moment.Therefore, there is only one effective running timer. In this case, thetimer controls the only one BWP regardless of whether the timer isassociated with the serving cell or the BWP. In a future 5G release, ona first bandwidth carrier, one terminal device has at least one activedownlink BWP or at least one uplink BWP in a serving cell at any moment.In this case, if a timer is associated with the serving cell, the timerneeds to control a plurality of BWPs. In contrast, if the timer isassociated with a BWP, there are a plurality of timers and each timercontrols one corresponding BWP. The following separately describesdifferent association scenarios by using specific embodiments, to bespecific, describes how to start or restart a timer when the timer isassociated with a serving cell or the timer is associated with a BWP. Itshould be noted that, if the term BWP appears, BWP may be understood asa downlink BWP in the paired spectrum scenario and may be understood asa BWP pair in the unpaired spectrum.

In a first association scenario, when a timer is associated with aserving cell, the timer may be started or restarted in a plurality ofpossible implementations. The following describes in detail how to startor restart the timer in the plurality of possible implementations.

In one possible implementation, the terminal device may determine, basedon the scrambling identifier of the first message, whether to start orrestart the timer. FIG. 2 is a schematic diagram of a timer processingmethod according to an embodiment of this application. The timerprocessing method may include the following steps.

S201: A terminal device receives a first message sent by a networkdevice.

The first message indicates a downlink assignment or an uplink grant, orthe first message indicates bandwidth part BWP switching.

It should be noted that, the first message may be a message such asdownlink control information carried on a PDCCH. For example, receivingthe first message may be understood as receiving the PDCCH, or receivingthe downlink control information, or receiving the downlink controlinformation carried on the PDCCH, or receiving the downlink controlinformation sent by using the PDCCH. In a paired spectrum scenario, thefirst message may indicate a downlink assignment. When the first messageindicates a downlink assignment, whether to start or restart a timerfurther needs to be determined. Alternatively, the first message mayindicate an uplink grant. When the first message indicates an uplinkgrant, a timer is not started or restarted. Certainly, the first messagemay also indicate BWP switching, and a downlink BWP that is switched tobe not a default downlink BWP. In an unpaired spectrum scenario, becausean uplink BWP and a downlink BWP appear in pairs, that is, a pair ofuplink and downlink BWPs are both switched during BWP switching, adefault BWP may be considered as including a pair of uplink and downlinkBWPs. In this case, the first message indicates a downlink assignment oran uplink grant (uplink grant), or the first message indicates BWPswitching and a BWP pair that is switched to is not a default BWP pair.

The paired spectrum scenario and the unpaired spectrum scenario aredifferent, and therefore methods for starting or restarting a timerbased on a scrambling identifier of the first message are also differentand respectively correspond to S202 and S203.

S202: If an active downlink BWP of the terminal device is not a defaultdownlink BWP, the terminal device starts or restarts a timer based on ascrambling identifier of the first message.

The timer is a timer used by the terminal device to switch from theactive downlink BWP to the default downlink BWP, or the timer is a timerused by the terminal device to activate the default downlink BWP anddeactivate the active downlink BWP. In the paired spectrum scenario, ifthe first message indicates a downlink assignment and does not indicateBWP switching, it may be considered that the active downlink BWP of theterminal device is a downlink BWP used for receiving the first message;or if the first message indicates bandwidth part BWP switching, it maybe considered that the active downlink BWP of the terminal device is adownlink BWP that is switched to. Alternatively, it may be consideredthat the active downlink BWP of the terminal device is a BWP indicatedby the first message, for example, an active downlink BWP indicated inthe downlink control information.

It should be noted that, the scrambling identifier of the first messageherein is a radio network temporary identifier used to scramble a cyclicredundancy check (Cyclic Redundancy Check, CRC) code of the firstmessage. For example, when the first message is downlink controlinformation, the scrambling identifier is a radio network temporaryidentifier used to scramble a cyclic redundancy check code of thedownlink control information. Scrambling the first message may beunderstood as scrambling the cyclic redundancy check code of the firstmessage.

In the solution shown in S202, in the paired spectrum scenario, afterthe terminal device receives the first message indicating a downlinkassignment, or after the terminal device receives the first messageindicating BWP switching and the downlink BWP that is switched to is notthe default downlink BWP, if the active downlink BWP of the terminaldevice is not the default downlink BWP in this case, the terminal devicemay start or restart the timer based on the scrambling identifier of thefirst message, wherein the timer is a timer used by the terminal deviceto switch from the active downlink BWP to the default downlink BWP, orthe timer is a timer used by the terminal device to activate the defaultdownlink BWP and deactivate the active downlink BWP. This avoidsprior-art practice that a timer is directly started or restarted after aPDCCH is directly received, and resolves a problem that the terminaldevice cannot correctly switch to the default downlink BWP and powerconsumption of the terminal device cannot be reduced, thereby reducingthe power consumption of the terminal device.

S203: If an active BWP pair of the terminal device is not a default BWPpair, the terminal device starts or restarts a timer based on ascrambling identifier of the first message.

The timer is a timer used by the terminal device to switch from theactive BWP pair to the default BWP pair, or the timer is a timer used bythe terminal device to activate the default BWP pair and deactivate theactive BWP pair.

In the unpaired spectrum scenario, if the first message indicates adownlink assignment or an uplink grant and does not indicate BWPswitching, it may be considered that the active BWP pair of the terminaldevice is a BWP pair that is corresponding to a downlink BWP used forreceiving the first message or a BWP pair to which a downlink BWP usedfor receiving the first message belongs; or if the first messageindicates bandwidth part BWP switching, it may be considered that theactive BWP pair of the terminal device is a BWP pair that is switchedto. Alternatively, it may be considered that the active BWP pair of theterminal device is a BWP pair indicated by the first message, forexample, an active BWP pair indicated in the downlink controlinformation. Alternatively, it may be considered that the active BWPpair of the terminal device is a BWP pair that is corresponding to adownlink BWP indicated by the first message or a BWP pair to which adownlink BWP indicated by the first message belongs, for example, anactive BWP pair that is corresponding to a downlink BWP indicated in thedownlink control information or an active BWP pair to which a downlinkBWP indicated in the downlink control information belongs.

In the solution shown in S203, in the unpaired spectrum scenario, afterthe terminal device receives the first message indicating an uplinkgrant or a downlink assignment, or after the terminal device receivesthe first message indicating BWP switching and the BWP pair that isswitched to is not the default BWP pair, if the active BWP pair of theterminal device is not the default BWP pair in this case, the terminaldevice may start or restart the timer based on the scrambling identifierof the first message, wherein the timer is a timer used by the terminaldevice to switch from the active BWP pair to the default BWP pair, orthe timer is a timer used by the terminal device to activate the defaultBWP pair and deactivate the active BWP pair. This avoids prior-artpractice that a timer is directly started or restarted after a PDCCH isdirectly received, and resolves a problem that the terminal devicecannot correctly switch to the default BWP pair and power consumption ofthe terminal device cannot be reduced, thereby reducing the powerconsumption of the terminal device.

It should be noted that, in one scheduling process, only either S202 orS203 is executed after S201 is executed, in other words, S202 and S203are not synchronously executed.

In S202 or S203 above, a different active BWP of the terminal deviceleads to a different manner of starting or restarting the timer based onthe scrambling identifier of the first message. However, controlconditions for starting or restarting the timer in these two manners arethe same, to be specific, control conditions for the terminal device tostart or restart the timer based on the scrambling identifier of thefirst message in S202 and S203 are the same. The terminal device maystart or restart the timer based on the scrambling identifier of thefirst message in the following possible manners:

Manner 1: The terminal device starts or restarts the timer when thescrambling identifier is not a random access radio network temporaryidentifier RA-RNTI or a temporary cell radio network temporaryidentifier TC-RNTI.

It should be noted that, for the RA-RNTI, the timer needs to be stoppedin a random access triggering process. In other words, that the timer isin a running state which is not expected in a random access process, toavoid a case in which the timer expires in the random access process.The first message scrambled by using the RA-RNTI schedules a randomaccess response (Random Access Response, RAR), that is, a message 2 inthe random access process. In a contention-based random access process,receiving an RAR does not mean that contention is successfullyaddressed, that is, the random access process may fail. If a timer isstarted immediately after the first message scrambled by using theRA-RNTI is received, the timer may expire in the random access process,or the timer may be incorrectly in the running state when random accessfails.

It should be noted that, for the TC-RNTI, only a contention-based randomaccess process in which the terminal device is in an idle (idle) stateoccurs. In this case, the idle-state terminal device works on an initialBWP. A PDCCH scrambled by using a TC-RNTI schedules a message in arandom access process. In this case, user equipment in the idle statehas not received a configuration message of a base station, in otherwords, there is no concept of a default BWP. Therefore, the TC-RNTI isunrelated to timer start or restart.

In the manner 1, after receiving the first message, the terminal devicedetermines whether the scrambling identifier that is used to scramblethe first message is the RA-RNTI or TC-RNTI. If the scramblingidentifier is not the RA-RNTI or TC-RNTI, it indicates that the terminaldevice may start or restart the timer. In this case, the terminal devicestarts or restarts the timer based on the scrambling identifier. Thisavoids a case in which the timer expires in the random access process ora case in which the timer is incorrectly in the running state whenrandom access fails, and resolves a problem that the terminal devicecannot correctly switch to the default downlink BWP and powerconsumption of the terminal device cannot be reduced, thereby reducingthe power consumption of the terminal device.

The manner 1 describes a case in which the timer is directly started orrestarted when the scrambling identifier of the first message is not theRA-RNTI. Conversely, if the scrambling identifier of the first messageis the RA-RNTI, a manner of executing random access by the terminaldevice further needs to be determined, to determine whether to start orrestart the timer, as described in a manner 2 below:

Manner 2: When the scrambling identifier is the random access radionetwork temporary identifier RA-RNTI, and the terminal device executesnon-contention-based random access, the terminal device starts orrestarts the timer. When the scrambling identifier is the RA-RNTI, andthe terminal device executes contention-based random access, theterminal device controls the timer to maintain an original state.

In the manner 2, receiving a random access response by the terminaldevice in the contention-based random access process does not mean thatcontention is successfully addressed, to be specific, the random accessprocess may fail. If the timer is started immediately after the firstmessage scrambled by using the RA-RNTI is received, the timer may expirein the random access process, or the timer may be incorrectly in therunning state when random access fails. Therefore, when determining thatthe scrambling identifier of the first message is the RA-RNTI and theterminal device executes contention-based random access, the terminaldevice does not start or restart the timer, that is, the timer maintainsthe original state. In contrast, receiving a random access response bythe terminal device in the non-contention-based random access processmeans that contention is successfully addressed. Therefore, whendetermining that the scrambling identifier of the first message is theRA-RNTI and the terminal executes non-contention-based random access,the terminal device directly controls the timer to start or restart, orstarts or restarts the timer after the first message scrambled by usingthe C-RNTI is dynamically received for the first time. This avoids acase in which the timer expires in the random access process or a casein which the timer is incorrectly in the running state when randomaccess fails, and resolves a problem that the terminal device cannotcorrectly switch to the default downlink BWP and power consumption ofthe terminal device cannot be reduced, thereby reducing the powerconsumption of the terminal device.

Manner 3: When the scrambling identifier is a first scramblingidentifier, the terminal device starts or restarts the timer.

The first scrambling identifier is any one or a combination of a cellradio network temporary identifier C-RNTI, a configured scheduling radionetwork temporary identifier CS-RNTI, a paging radio network temporaryidentifier P-RNTI, and a system information radio network temporaryidentifier SI-RNTI.

It should be noted that, the first scrambling identifier may be any oneor a combination of the foregoing four radio network temporaryidentifiers. To be specific, any one of the foregoing four radio networktemporary identifiers may be selected to scramble the first message, orany two or three of the foregoing four radio network temporaryidentifiers may be selected to scramble the first message. Certainly,alternatively, the foregoing four radio network temporary identifiersmay all be selected to scramble the first message.

Similarly, in the manner 3, after receiving the first message, theterminal device judges the scrambling identifier used to scramble thefirst message. If the scrambling identifier is the first scramblingidentifier, it indicates that the terminal device may start or restartthe timer. In this case, the terminal device starts or restarts thetimer based on the scrambling identifier. This resolves a problem thatthe terminal device cannot correctly switch to the default downlink BWPand power consumption of the terminal device cannot be reduced, therebyreducing the power consumption of the terminal device.

According to the timer processing method provided in this embodiment ofthe present invention, during determining of whether to start or restarta timer, the terminal device receives the first message sent by thenetwork device. If the active downlink bandwidth part BWP of theterminal device is not the default downlink BWP, the terminal devicestarts or restarts a timer based on the scrambling identifier of thefirst message, wherein the timer is a timer used by the terminal deviceto switch from the active downlink BWP to the default downlink BWP, orthe timer is a timer used by the terminal device to activate the defaultdownlink BWP and deactivate the active downlink BWP. If the active BWPpair of the terminal device is not the default BWP pair, the terminaldevice starts or restarts a timer based on the scrambling identifier ofthe first message, wherein the timer is a timer used by the terminaldevice to switch from the active BWP pair to the default BWP pair, orthe timer is a timer used by the terminal device to activate the defaultBWP pair and deactivate the active BWP pair. This resolves a problemthat the terminal device cannot correctly switch to the default downlinkBWP and power consumption of the terminal device cannot be reduced,thereby reducing the power consumption of the terminal device.

The embodiment shown in FIG. 2 describes in detail the solution abouthow the terminal device determines, based on the scrambling identifierof the first message, whether to start or restart a timer. The followingdescribes in detail another possible implementation in which theterminal device may determine, based on a carrier index of the firstmessage, whether to start or restart a timer. For example, the timerprocessing method is applicable to a carrier aggregation scenario. FIG.3 is a schematic diagram of another timer processing method according toan embodiment of the present invention. The timer processing method mayinclude the following steps.

S301: A terminal device receives a first message sent by a networkdevice.

The first message indicates a downlink assignment or an uplink grant, orthe first message is used to indicate bandwidth part BWP switching.

It should also be noted that, the first message may be a message such asdownlink control information carried on a PDCCH. Receiving the firstmessage may be understood as receiving the PDCCH, or receiving thedownlink control information, or receiving the downlink controlinformation carried on the PDCCH, or receiving the downlink controlinformation sent by using the PDCCH. In a paired spectrum scenario, thefirst message indicates a downlink assignment, or the first messageindicates BWP switching and a downlink BWP that is switched to is not adefault downlink BWP. In an unpaired spectrum scenario, because anuplink BWP and a downlink BWP appear in pairs, that is, a pair of uplinkand downlink BWPs are both switched during BWP switching, a default BWPmay be considered as including a pair of uplink and downlink BWPs. Inthis case, the first message indicates a downlink assignment or anuplink grant (uplink grant), or the first message indicates BWPswitching and a BWP pair that is switched to is not a default BWP pair.

S302: The terminal device starts or restarts a timer based on a carrierindex of the first message.

The timer is a timer used by the terminal device to switch from anactive downlink BWP to a default downlink BWP, or the timer is a timerused by the terminal device to activate a default downlink BWP anddeactivate an active downlink BWP, or the timer is a timer used by theterminal device to switch from an active BWP pair to the default BWPpair, or the timer is a timer used by the terminal device to activatethe default BWP pair and deactivate an active BWP pair.

It should be noted that, the carrier index of the first message hereinmay be understood as a carrier index in the first message, or a carrierindex indicated by the first message, or a carrier index included by thefirst message, or certainly, a carrier index carried by the firstmessage.

The paired spectrum scenario and the unpaired spectrum scenario aredifferent, and therefore timers started or restarted based on thecarrier index of the first message are also different. A detaileddescription is as follows.

In one scenario, namely, the paired spectrum scenario, if the activedownlink BWP of the terminal device is not the default downlink BWP andthe active downlink BWP of the terminal device is a downlink BWP of acarrier or a serving cell indicated by the carrier index, the timer is atimer of the carrier or the serving cell.

The timer is a timer used by the terminal device to switch from theactive downlink BWP to the default downlink BWP, or the timer is a timerused by the terminal device to activate the default downlink BWP anddeactivate the active downlink BWP.

In the paired spectrum scenario, if the first message indicates adownlink assignment and does not indicate BWP switching, it may beconsidered that the active downlink BWP of the terminal device is adownlink BWP used for receiving the first message; or if the firstmessage indicates bandwidth part BWP switching, it may be consideredthat the active downlink BWP of the terminal device is a downlink BWPthat is switched to. Alternatively, it may be considered that the activedownlink BWP of the terminal device is a BWP indicated by the firstmessage, for example, an active downlink BWP indicated in the downlinkcontrol information.

In the paired spectrum scenario, if the active downlink bandwidth partBWP of the terminal device is not the default downlink BWP, and theactive downlink BWP of the terminal device is a downlink BWP of acarrier or a serving cell indicated by the carrier index, or the activedownlink BWP of the terminal device is a downlink BWP of a carrier or aserving cell with data transmitted, the timer is a timer of the carrieror the serving cell indicated by the carrier index. For example, withcross-carrier scheduling in the carrier aggregation scenario, thecarrier or the serving cell indicated by the carrier index is differentfrom a carrier or a serving cell used for receiving the first message.The terminal device receives the first message on a carrier 1 or in aserving cell 1, and the carrier or the serving cell indicated by thecarrier index of the first message is a carrier 2 or a serving cell 2.If the downlink BWP of the carrier or the serving cell indicated by thecarrier index is not the default downlink BWP, the timer is the timer ofthe carrier or the serving cell indicated by the carrier index, namely,a timer of the carrier 2 or the serving cell 2.

Optionally, further, if the active downlink BWP of the terminal deviceis not the default downlink BWP and the active downlink BWP of theterminal device is a downlink BWP of the carrier or the serving cellused for receiving the first message, the timer is a timer of thecarrier or the serving cell used for receiving the first message. Forexample, with cross-carrier scheduling in the carrier aggregationscenario, the carrier or the serving cell indicated by the carrier indexis different from a carrier or a serving cell used for receiving thefirst message. The terminal device receives the first message on acarrier 1 or in a serving cell 1, and the carrier or the serving cellindicated by the carrier index of the first message is a carrier 2 or aserving cell 2. If the downlink BWP of the carrier or the serving cellindicated by the carrier index is not the default downlink BWP, thetimer is the timer of the carrier or the serving cell indicated by thecarrier index, namely, a timer of the carrier 2 or the serving cell 2.If the downlink BWP of the carrier or the serving cell used forreceiving the first message is not the default downlink BWP, the timeris the timer of the carrier or the serving cell used for receiving thefirst message, namely, a timer of the carrier 1 or the serving cell 1.In other words, when the foregoing conditions are met, started orrestarted timers include the timer of the carrier or the serving cellindicated by the carrier index and the timer of the carrier or theserving cell used for receiving the first message. This resolves aproblem that the terminal device cannot correctly switch to the defaultdownlink BWP and power consumption of the terminal device cannot bereduced, thereby reducing the power consumption of the terminal device.

In another scenario, namely, the unpaired spectrum scenario, if theactive BWP pair of the terminal device is not the default BWP pair andthe active BWP pair of the terminal device is a BWP pair of a carrier ora serving cell indicated by the carrier index, the timer is a timer ofthe carrier or the serving cell.

The timer is a timer used by the terminal device to switch from theactive BWP pair to the default BWP pair, or the timer is a timer used bythe terminal device to activate the default BWP pair and deactivate theactive BWP pair.

In the unpaired spectrum scenario, if the first message indicates adownlink assignment or an uplink grant and does not indicate BWPswitching, it may be considered that the active BWP pair of the terminaldevice is a BWP pair that is corresponding to a downlink BWP used forreceiving the first message or a BWP pair to which a downlink BWP usedfor receiving the first message belongs; or if the first messageindicates bandwidth part BWP switching, it may be considered that theactive BWP pair of the terminal device is a BWP pair that is switchedto. Alternatively, it may be considered that the active BWP pair of theterminal device is a BWP pair indicated by the first message, forexample, an active BWP pair indicated in the downlink controlinformation. Alternatively, it may be considered that the active BWPpair of the terminal device is a BWP pair that is corresponding to adownlink BWP indicated by the first message or a BWP pair to which adownlink BWP indicated by the first message belongs, for example, anactive BWP pair that is corresponding to a downlink BWP indicated in thedownlink control information or an active BWP pair to which a downlinkBWP indicated in the downlink control information belongs.

In the unpaired spectrum scenario, if the active bandwidth part BWP pairof the terminal device is not the default BWP pair, and the active BWPpair of the terminal device is a BWP pair of a carrier or a serving cellindicated by the carrier index, or the active BWP pair of the terminaldevice is a BWP pair of a carrier or a serving cell with datatransmitted, the timer is a timer of the carrier or the serving cellindicated by the carrier index. For example, with cross-carrierscheduling in the carrier aggregation scenario, the carrier or theserving cell indicated by the carrier index is different from a carrieror a serving cell used for receiving the first message. The terminaldevice receives the first message on a carrier 1 or in a serving cell 1,and the carrier or the serving cell indicated by the carrier index ofthe first message is a carrier 2 or a serving cell 2. If the BWP pair ofthe carrier or the serving cell indicated by the carrier index is notthe default BWP pair, the timer is the timer of the carrier or theserving cell indicated by the carrier index, namely, a timer of thecarrier 2 or the serving cell 2.

Optionally, further, if the active BWP pair of the terminal device isnot the default BWP pair and the active BWP pair of the terminal deviceis a BWP pair of the carrier or the serving cell used for receiving thefirst message, the timer is a timer of the carrier or the serving cellused for receiving the first message. For example, with cross-carrierscheduling in the carrier aggregation scenario, the carrier or theserving cell indicated by the carrier index is different from a carrieror a serving cell used for receiving the first message. The terminaldevice receives the first message on a carrier 1 or in a serving cell 1,and the carrier or the serving cell indicated by the carrier index ofthe first message is a carrier 2 or a serving cell 2. If the BWP pair ofthe carrier or the serving cell indicated by the carrier index is notthe default BWP pair, the timer is the timer of the carrier or theserving cell indicated by the carrier index, namely, a timer of thecarrier 2 or the serving cell 2. If the BWP pair of the carrier or theserving cell used for receiving the first message is not the default BWPpair, the timer is the timer of the carrier or the serving cell used forreceiving the first message, namely, a timer of the carrier 1 or theserving cell 1. In other words, when the foregoing conditions are met,started or restarted timers include the timer of the carrier or theserving cell indicated by the carrier index and the timer of the carrieror the serving cell used for receiving the first message. This resolvesa problem that the terminal device cannot correctly switch to thedefault downlink BWP and power consumption of the terminal device cannotbe reduced, thereby reducing the power consumption of the terminaldevice.

According to the timer processing method provided in this embodiment ofthe present invention, during determining of whether to start or restarta timer, the terminal device receives the first message sent by thenetwork device. The terminal device starts or restarts the timer basedon the carrier index of the first message, wherein the timer is a timerused by the terminal device to switch from the active downlink BWP tothe default downlink BWP, or the timer is a timer used by the terminaldevice to activate the default downlink BWP and deactivate the activedownlink BWP, or the timer is a timer used by the terminal device toswitch from the active BWP pair to the default BWP pair, or the timer isa timer used by the terminal device to activate the default BWP pair anddeactivate the active BWP pair. This resolves a problem that theterminal device cannot correctly switch to the default downlink BWP andpower consumption of the terminal device cannot be reduced, therebyreducing the power consumption of the terminal device.

The embodiment shown in FIG. 3 describes in detail the solution abouthow the terminal device determines, based on the carrier index of thefirst message, whether to start or restart a timer. In addition, a timeris started or restarted only when a PDCCH is received in the prior art.Therefore, there is no timer restart condition in a non-dynamicscheduling process, and the terminal device may fall back to a defaultBWP in the non-dynamic scheduling process. Consequently, current datatransmission of the terminal device is affected. Therefore, in anembodiment of the present invention, a description about how to start orrestart a timer in the non-dynamic scheduling process is added. FIG. 4is a schematic diagram of another timer processing method according toan embodiment of the present invention. The timer processing method mayinclude the following steps.

S401: A terminal device determines that at least one configured resourceexists.

It should also be noted that, in a paired spectrum scenario, an activedownlink BWP of the terminal device is not a default downlink BWP. In anunpaired spectrum scenario, because an uplink BWP and a downlink BWPappear in pairs, that is, a pair of uplink and downlink BWPs are bothswitched during BWP switching, a default BWP may be considered asincluding a pair of uplink and downlink BWPs. In this case, an activeBWP pair of the terminal device is not a default BWP pair.

It should be noted that, that at least one configured resource existsherein may be understood as the following: there is at least oneconfigured resource, or at least one configured resource appears, orcertainly, at least one configured resource occurs, or the like.

As there are different scenarios, methods for starting or restarting, bythe terminal device, a timer based on the at least one configuredresource that exists are different, and respectively correspond to S402and S403.

S402: If an active downlink BWP of the terminal device is not a defaultdownlink BWP, the terminal device starts or restarts a timer based onthe at least one configured resource that exists.

The timer is a timer used by the terminal device to switch from theactive downlink BWP to the default downlink BWP, or the timer is a timerused by the terminal device to activate the default downlink BWP anddeactivate the active downlink BWP.

In the solution shown in S402, in the paired spectrum scenario, if theactive downlink BWP of the terminal device is not the default downlinkBWP and the configured resource is a downlink resource, the terminaldevice may start or restart the timer based on the at least oneconfigured resource that exists.

Optionally, that the terminal device starts or restarts a timer based onthe at least one configured resource that exists in S402 may include thefollowing possible manners:

Manner 1: The terminal device starts or restarts the timer when theterminal device determines that the at least one configured resourceexists.

In the manner 1, for example, with non-dynamic scheduling, for example,downlink semi-persistent scheduling (Semi-Persistent Scheduling, SPS),when the terminal device determines that at least one configureddownlink resource exists, that is, at least one configured downlinkassignment (downlink assignment) exists, the terminal device starts orrestarts the timer, wherein the timer is a timer used by the terminaldevice to switch from the active downlink BWP to the default downlinkBWP, or the timer is a timer used by the terminal device to activate thedefault downlink BWP and deactivate the active downlink BWP. This avoidsa prior-art problem that the terminal device may fall back to a defaultBWP in a non-dynamic scheduling process because a timer is started orrestarted only when a PDCCH is received, thereby avoiding impact oncurrent data transmission of the terminal device. It should be notedthat, the at least one configured resource is at least one configuredresource on the active downlink BWP of the terminal device.

The manner 1 describes direct timer start or restart performed when atleast one configured resource exists. Certainly, whether data istransmitted on the configured resource may further be determined, todetermine whether to start or restart the timer, as described in amanner 2 below:

Manner 2: When determining that there is data transmitted on theconfigured resource, the terminal device starts or restarts the timer.

In the manner 2, the terminal device does not start or restart the timerafter determining that at least one configured resource exists. Instead,the terminal device further determines whether data is transmitted onthe configured resource. For example, with non-dynamic scheduling, forexample, downlink semi-persistent scheduling (Semi-PersistentScheduling, SPS), when the terminal device determines that downlink datais transmitted on at least one configured downlink resource, that is,downlink data is transmitted on at least one configured downlinkassignment (downlink assignment), the terminal device starts or restartsthe timer, wherein the timer is a timer used by the terminal device toswitch from the active downlink BWP to the default downlink BWP, or thetimer is a timer used by the terminal device to activate the defaultdownlink BWP and deactivate the active downlink BWP. This avoids aprior-art problem that the terminal device may fall back to a defaultBWP in a non-dynamic scheduling process because a timer is started orrestarted only when a PDCCH is received, thereby avoiding impact oncurrent data transmission of the terminal device. It should be notedthat, the data transmission is data transmission on the active downlinkBWP of the terminal device.

S403: If an active BWP pair of the terminal device is not a default BWPpair, the terminal device starts or restarts a timer based on the atleast one configured resource that exists.

The timer is a timer used by the terminal device to switch from theactive BWP pair to the default BWP pair, or the timer is a timer used bythe terminal device to activate the default BWP pair and deactivate theactive BWP pair.

In the solution shown in S403, in the unpaired spectrum scenario, if theactive BWP pair of the terminal device is not the default BWP pair andthe configured resource is a downlink resource or an uplink resource,the terminal device may start or restart the timer based on the at leastone configured resource that exists.

Optionally, that the terminal device starts or restarts a timer based onthe at least one configured resource that exists in S403 may include thefollowing possible manners:

Manner 1: The terminal device starts or restarts the timer when theterminal device determines that the at least one configured resourceexists.

In the manner 1, for example, with non-dynamic scheduling, for example,downlink semi-persistent scheduling (Semi-Persistent Scheduling, SPS),grant free (Grant Free, GF) scheduling, or uplink semi-persistentscheduling, wherein the grant free (Grant Free, GF) scheduling is alsoreferred to as a configured grant type 1 (configured grant Type 1) andthe uplink semi-persistent scheduling is also referred to as aconfigured grant type 2 (configured grant Type 2), when the terminaldevice determines that at least one configured downlink resource orconfigured uplink resource exists, that is, at least one configureddownlink assignment (downlink assignment) exists or at least oneconfigured uplink grant (uplink grant) exists, the terminal devicestarts or restarts the timer, wherein the timer is a timer used by theterminal device to switch from the active downlink BWP pair to thedefault downlink BWP pair, or the timer is a timer used by the terminaldevice to activate the default BWP pair and deactivate the active BWPpair. This avoids a prior-art problem that the terminal device may fallback to a default BWP in a non-dynamic scheduling process because atimer is started or restarted only when a PDCCH is received, therebyavoiding impact on current data transmission of the terminal device. Itshould be noted that, the at least one configured resource is at leastone configured resource on the active BWP pair of the terminal device.

The manner 1 describes direct timer start or restart performed when atleast one configured resource exists. Certainly, whether data istransmitted on the configured resource may further be determined, todetermine whether to start or restart the timer, as described in amanner 2 below:

Manner 2: When the terminal device transmits data on the determinedconfigured resource, the terminal device starts or restarts the timer.

In the manner 2, the terminal device does not start or restart the timerafter determining that at least one configured resource exists. Instead,the terminal device further determines whether data is transmitted onthe configured resource. For example, with non-dynamic scheduling, forexample, downlink semi-persistent scheduling (Semi-PersistentScheduling, SPS), grant free (Grant Free, GF) scheduling, or uplinksemi-persistent scheduling, wherein the grant free (Grant Free, GF)scheduling is also referred to as a configured grant type 1 (configuredgrant Type 1) and the uplink semi-persistent scheduling is also referredto as a configured grant type 2 (configured grant Type 2), when theterminal device determines that downlink data is transmitted on at leastone configured downlink resource, that is, downlink data is transmittedon at least one configured downlink assignment (downlink assignment),the terminal device starts or restarts the timer; or when the terminaldevice determines that uplink data is transmitted on at least oneconfigured uplink resource, that is, uplink data is transmitted on atleast one configured uplink grant (uplink grant), the terminal devicestarts or restarts the timer, wherein the timer is a timer used by theterminal device to switch from the active BWP pair to the default BWPpair, or the timer is a timer used by the terminal device to activatethe default downlink BWP pair and deactivate the active downlink BWPpair. This avoids a prior-art problem that the terminal device may fallback to a default BWP in a non-dynamic scheduling process because atimer is started or restarted only when a PDCCH is received, therebyavoiding impact on current data transmission of the terminal device. Itshould be noted that, the data transmission is data transmission on theactive BWP pair of the terminal device.

It should be noted that, in one scheduling process, only either S402 orS403 is executed after S401 is executed, in other words, S402 and S403are not synchronously executed.

According to the timer processing method provided in this embodiment ofthe present invention, during determining of whether to start or restarta timer, the terminal device determines that at least one configuredresource exists or determines that data is transmitted on the at leastone configured resource. If the active downlink BWP of the terminaldevice is not the default downlink BWP, the terminal device starts orrestarts the timer based on the at least one configured resource thatexists or the terminal device starts or restarts the timer based on afact that data is transmitted on the at least one configured resource,wherein the timer is a timer used by the terminal device to switch fromthe active downlink BWP to the default downlink BWP, or the timer is atimer used by the terminal device to activate the default downlink BWPand deactivate the active downlink BWP; if the active BWP pair of theterminal device is not the default BWP pair, the terminal device startsor restarts the timer based on the at least one configured resource thatexists or the terminal device starts or restarts the timer based on afact that data is transmitted on the at least one configured resource,wherein the timer is a timer used by the terminal device to switch fromthe active BWP pair to the default BWP pair, or the timer is a timerused by the terminal device to activate the default BWP pair anddeactivate the active BWP pair. This resolves a problem that theterminal device falls back to a default BWP in a non-dynamic schedulingprocess, thereby avoiding impact on current data transmission of theterminal device.

It should be noted that, the timer in the embodiments shown in FIG. 2 toFIG. 4 may further be another type of timer. The another type of timermay be a timer used by the terminal device to deactivate the activedownlink BWP, or the another type of timer may be used by the terminaldevice to deactivate the active BWP pair of the terminal device. Inaddition, it should be noted that, the downlink BWP in the pairedspectrum scenario may represent a downlink BWP in a BWP pair, and mayalso represent an uplink BWP paired with the downlink BWP, in otherwords, the downlink BWP may be understood as a BWP pair corresponding tothe downlink BWP.

The embodiments shown in FIG. 2 to FIG. 4 describe in detail thetechnical solutions about how to start or restart a timer when the timeris associated with a serving cell. The following describes in detail howthe terminal device starts or restarts a timer when the timer isassociated with a BWP in a second association scenario.

In one possible implementation, the terminal device may determine, basedon the scrambling identifier of the first message, whether to start orrestart the timer. FIG. 5 is a schematic diagram of a timer processingmethod according to an embodiment of this application. The timerprocessing method may include the following steps.

S501: A terminal device receives a first message sent by a networkdevice.

The first message indicates a downlink assignment or an uplink grant, orthe first message indicates bandwidth part BWP switching.

It should be noted that, the first message may be a message such asdownlink control information carried on a PDCCH. For example, receivingthe first message may be understood as receiving the PDCCH, or receivingthe downlink control information, or receiving the downlink controlinformation carried on the PDCCH, or receiving the downlink controlinformation sent by using the PDCCH. In a paired spectrum scenario, thefirst message may indicate a downlink assignment. When the first messageindicates a downlink assignment, whether to start or restart a timerfurther needs to be determined. Alternatively, the first message mayindicate an uplink grant. When the first message indicates an uplinkgrant, a timer is not started or restarted. Certainly, the first messagemay also indicate BWP switching, and a downlink BWP that is switched tois not a default downlink BWP. In an unpaired spectrum scenario, becausean uplink BWP and a downlink BWP appear in pairs, that is, a pair ofuplink and downlink BWPs are both switched during BWP switching, adefault BWP may be considered as including a pair of uplink and downlinkBWPs. In this case, the first message indicates a downlink assignment oran uplink grant (uplink grant), or the first message indicates BWPswitching and a BWP pair that is switched to is not a default BWP pair.

The paired spectrum scenario and the unpaired spectrum scenario aredifferent, and therefore methods for starting or restarting a timerbased on a scrambling identifier of the first message are also differentand respectively correspond to S202 and S203.

S502: If an active downlink BWP of the terminal device is not a defaultdownlink BWP, the terminal device starts or restarts, based on ascrambling identifier of the first message, a timer associated with theactive downlink BWP.

The timer is a timer used by the terminal device to switch from theactive downlink BWP to the default downlink BWP, or the timer is a timerused by the terminal device to activate the default downlink BWP anddeactivate the active downlink BWP.

In the paired spectrum scenario, if the first message indicates adownlink assignment and does not indicate BWP switching, it may beconsidered that the active downlink BWP of the terminal device is adownlink BWP used for receiving the first message; or if the firstmessage indicates bandwidth part BWP switching, it may be consideredthat the active downlink BWP of the terminal device is a downlink BWPthat is switched to. Alternatively, it may be considered that the activedownlink BWP of the terminal device is a BWP indicated by the firstmessage, for example, an active downlink BWP indicated in the downlinkcontrol information.

It should be noted that, the scrambling identifier of the first messageherein is a radio network temporary identifier used to scramble a cyclicredundancy check (Cyclic Redundancy Check, CRC) code of the firstmessage. For example, when the first message is downlink controlinformation, the scrambling identifier is a radio network temporaryidentifier used to scramble a cyclic redundancy check code of thedownlink control information. Scrambling the first message may beunderstood as scrambling the cyclic redundancy check code of the firstmessage.

It should be noted that, in the paired spectrum scenario in which atimer is associated with a BWP, if the active downlink BWP of theterminal device is not the default downlink BWP, when the terminaldevice starts or restarts the timer based on the scrambling identifierof the first message, the timer is the timer associated with the activedownlink BWP of the terminal device. The following two possibilities maybe included:

Possibility 1: When the first message indicates a downlink assignmentand does not indicate BWP switching, it may be considered that theactive downlink BWP of the terminal device is a downlink BWP used forreceiving the first message, and the timer is a timer associated withthe downlink BWP used by the terminal device for receiving the firstmessage.

Possibility 2: When the first message indicates BWP switching and adownlink BWP that is switched to is not the default downlink BWP, it maybe considered that the active downlink BWP of the terminal device is thedownlink BWP that is switched to, and the timer is a timer associatedwith the downlink BWP that the terminal device is switched to. Forexample, the terminal device has two timers, which are a timer 1 and atimer 2, and the timer 1 is associated with a downlink BWP 1 and thetimer 2 is associated with a downlink BWP 2. After the terminal devicereceives a first message used to indicate switching from the currentactive downlink BWP 1 to the downlink BWP 2 that is not the defaultdownlink BWP, the terminal device needs to switch from the currentdownlink BWP 1 to the downlink BWP 2. When the terminal devicedetermines to deactivate the active downlink BWP 1, the terminal devicestops the timer associated with the to-be-deactivated downlink BWP 1, tobe specific, when the terminal device determines to activate thedownlink BWP 2 and deactivate the downlink BWP 1, correspondingly, theterminal device needs to start or restart the timer 2 associated withthe to-be-activated downlink BWP 2 and stops the timer 1 associated withthe to-be-deactivated downlink BWP 1. It should be noted that, in thisembodiment of this application, the method may further include: When theterminal device determines to deactivate the active downlink BWP, theterminal device stops the timer associated with the to-be-deactivateddownlink BWP; or when the terminal device determines to deactivate anactive BWP pair, the terminal device stops a timer associated with theto-be-deactivated BWP pair. The terminal device determines, based on thefirst message, to deactivate the active downlink BWP, and stops thetimer associated with the to-be-deactivated downlink BWP. In addition,when determining that the timer expires, the terminal device determinesto deactivate the active downlink BWP and stops the timer associatedwith the to-be-deactivated downlink BWP.

In the solution shown in S502, after the terminal device receives thefirst message indicating a downlink assignment, or after the terminaldevice receives the first message indicating BWP switching and thedownlink BWP that is switched to is not the default downlink BWP, if theactive downlink BWP of the terminal device is not the default downlinkBWP in this case, the terminal device may start or restart the timerbased on the scrambling identifier of the first message, wherein thetimer is a timer used by the terminal device to switch from the activedownlink BWP to the default downlink BWP, or the timer is a timer usedby the terminal device to activate the default downlink BWP anddeactivate the active downlink BWP. This avoids prior-art practice thata timer is directly started or restarted after a PDCCH is directlyreceived, and resolves a problem that the terminal device cannotcorrectly switch to the default downlink BWP and power consumption ofthe terminal device cannot be reduced, thereby reducing the powerconsumption of the terminal device.

S503: If an active BWP pair of the terminal device is not a default BWPpair, the terminal device starts or restarts, based on a scramblingidentifier of the first message, a timer associated with the active BWPpair.

The timer is a timer used by the terminal device to switch from theactive BWP pair to the default BWP pair, or the timer is a timer used bythe terminal device to activate the default BWP pair and deactivate theactive BWP pair.

In the unpaired spectrum scenario, if the first message indicates adownlink assignment or an uplink grant and does not indicate BWPswitching, it may be considered that the active BWP pair of the terminaldevice is a BWP pair that is corresponding to a downlink BWP used forreceiving the first message or a BWP pair to which a downlink BWP usedfor receiving the first message belongs; or if the first messageindicates bandwidth part BWP switching, it may be considered that theactive BWP pair of the terminal device is a BWP pair that is switchedto. Alternatively, it may be considered that the active BWP pair of theterminal device is a BWP pair indicated by the first message, forexample, an active BWP pair indicated in the downlink controlinformation. Alternatively, it may be considered that the active BWPpair of the terminal device is a BWP pair that is corresponding to adownlink BWP indicated by the first message or a BWP pair to which adownlink BWP indicated by the first message belongs, for example, anactive BWP pair that is corresponding to a downlink BWP indicated in thedownlink control information or an active BWP pair to which a downlinkBWP indicated in the downlink control information belongs.

It should be noted that, in the unpaired spectrum scenario in which atimer is associated with a BWP, if the active BWP pair of the terminaldevice is not the default BWP pair, when the terminal device starts orrestarts the timer based on the scrambling identifier of the firstmessage, the timer is the timer associated with the active BWP pair ofthe terminal device. The following two possibilities may be included:

Possibility 1: When the first message indicates a downlink assignment oran uplink grant and does not indicate BWP switching, it may beconsidered that the active downlink BWP of the terminal device is adownlink BWP used for receiving the first message, and the timer is atimer associated with a BWP pair used by the terminal device forreceiving the first message, or the timer is a timer associated with aBWP pair corresponding to the downlink BWP used by the terminal devicefor receiving the first message.

Possibility 2: When the first message indicates BWP switching and a BWPpair that is switched to is not the default BWP pair, it may beconsidered that the active BWP pair of the terminal device is the BWPpair that is switched to, and the timer is a timer associated with theBWP pair that the terminal device is switched to. For example, theterminal device has two timers, which are a timer 3 and a timer 4, andthe timer 3 is associated with a BWP 3 pair and the timer 4 isassociated with a BWP 4 pair. After the terminal device receives a firstmessage used to indicate switching from the current active BWP 3 pair tothe BWP 4 pair that is not the default BWP pair, the terminal deviceneeds to switch from the current BWP 3 pair to the BWP 4 pair. When theterminal device determines to deactivate the active BWP 3 pair, theterminal device stops the timer associated with the to-be-deactivatedBWP 3 pair, to be specific, when the terminal device determines toactivate the BWP 4 pair and deactivate the BWP 3 pair, correspondingly,the terminal device needs to start or restart the timer 4 associatedwith the to-be-activated BWP 4 pair and stops the timer 3 associatedwith the to-be-deactivated BWP 3 pair. It should be noted that, in thisembodiment of this application, the method may further include: When theterminal device determines to deactivate the active downlink BWP, theterminal device stops the timer associated with the to-be-deactivateddownlink BWP; or when the terminal device determines to deactivate theactive BWP pair, the terminal device stops the timer associated with theto-be-deactivated BWP pair. The terminal device determines, based on thefirst message, to deactivate the active BWP pair, and stops the timerassociated with the to-be-deactivated BWP pair. In addition, whendetermining that the timer expires, the terminal device determines todeactivate the active BWP pair and stops the timer associated with theto-be-deactivated BWP pair.

In the solution shown in S503, after the terminal device receives thefirst message indicating an uplink grant or a downlink assignment, orafter the terminal device receives the first message indicating BWPswitching and the BWP pair that is switched to is not the default BWPpair, if the active BWP pair of the terminal device is not the defaultBWP pair in this case, the terminal device may start or restart thetimer based on the scrambling identifier of the first message, whereinthe timer is a timer used by the terminal device to switch from theactive BWP pair to the default BWP pair, or the timer is a timer used bythe terminal device to activate the default BWP pair and deactivate theactive BWP pair. This avoids prior-art practice that a timer is directlystarted or restarted after a PDCCH is directly received, and resolves aproblem that the terminal device cannot correctly switch to the defaultBWP pair and power consumption of the terminal device cannot be reduced,thereby reducing the power consumption of the terminal device.

It should be noted that, in one scheduling process, only either S502 orS503 is executed after S501 is executed, in other words, S502 and S503are not synchronously executed.

In S502 or S503 above, a different active BWP of the terminal deviceleads to a different manner of starting or restarting the timer based onthe scrambling identifier of the first message. However, controlconditions for starting or restarting the timer in these two manners arethe same, to be specific, control conditions for the terminal device tostart or restart the timer based on the scrambling identifier of thefirst message in S502 and S503 are the same. The terminal device maystart or restart the timer based on the scrambling identifier of thefirst message in the following possible manners:

Manner 1: The terminal device starts or restarts the timer when thescrambling identifier is not a random access radio network temporaryidentifier RA-RNTI or a temporary cell radio network temporaryidentifier TC-RNTI.

It should be noted that, for the RA-RNTI, the timer needs to be stoppedin a random access triggering process. In other words, that the timer isin a running state is not expected in a random access process, to avoida case in which the timer expires in the random access process. Thefirst message scrambled by using the RA-RNTI schedules a random accessresponse (Random Access Response, RAR), that is, a message 2 in therandom access process. In a contention-based random access process,receiving an RAR does not mean that contention is successfullyaddressed, that is, the random access process may fail. If a timer isstarted immediately after the first message scrambled by using theRA-RNTI is received, the timer may expire in the random access process,or the timer may be incorrectly in the running state when random accessfails.

It should be noted that, for the TC-RNTI, only a contention-based randomaccess process in which the terminal device is in an idle (idle) stateoccurs. In this case, the idle-state terminal device works on an initialBWP. A PDCCH scrambled by using a TC-RNTI schedules a message in arandom access process. In this case, user equipment in the idle statehas not received a configuration message of a base station, in otherwords, there is no concept of a default BWP. Therefore, the TC-RNTI isunrelated to timer start or restart.

In the manner 1, after receiving the first message, the terminal devicedetermines whether the scrambling identifier that is used to scramblethe first message is the RA-RNTI or TC-RNTI. If the scramblingidentifier is not the RA-RNTI or TC-RNTI, it indicates that the terminaldevice may start or restart the timer. In this case, the terminal devicestarts or restarts the timer based on the scrambling identifier. Thisavoids a case in which the timer expires in the random access process ora case in which the timer is incorrectly in the running state whenrandom access fails, and resolves a problem that the terminal devicecannot correctly switch to the default downlink BWP and powerconsumption of the terminal device cannot be reduced, thereby reducingthe power consumption of the terminal device.

The manner 1 describes a case in which the timer is directly started orrestarted when the scrambling identifier of the first message is not theRA-RNTI. Conversely, if the scrambling identifier of the first messageis the RA-RNTI, a manner of executing random access by the terminaldevice further needs to be determined, to determine whether to start orrestart the timer, as described in a manner 2 below:

Manner 2: When the scrambling identifier is the random access radionetwork temporary identifier RA-RNTI, and the terminal device executesnon-contention-based random access, the terminal device starts orrestarts the timer. When the scrambling identifier is the RA-RNTI, andthe terminal device executes contention-based random access, theterminal device controls the timer to maintain an original state.

In the manner 2, receiving a random access response by the terminaldevice in the contention-based random access process does not mean thatcontention is successfully addressed, to be specific, the random accessprocess may fail. If the timer is started immediately after the firstmessage scrambled by using the RA-RNTI is received, the timer may expirein the random access process, or the timer may be incorrectly in therunning state when random access fails. Therefore, when determining thatthe scrambling identifier of the first message is the RA-RNTI and theterminal device executes contention-based random access, the terminaldevice does not start or restart the timer, that is, the timer maintainsthe original state. In contrast, receiving a random access response bythe terminal device in the non-contention-based random access processmeans that contention is successfully addressed. Therefore, whendetermining that the scrambling identifier of the first message is theRA-RNTI and the terminal executes non-contention-based random access,the terminal device directly controls the timer to start or restart, orstarts or restarts the timer after the first message scrambled by usingthe C-RNTI is dynamically received for the first time. This avoids acase in which the timer expires in the random access process or a casein which the timer is incorrectly in the running state when randomaccess fails, and resolves a problem that the terminal device cannotcorrectly switch to the default downlink BWP and power consumption ofthe terminal device cannot be reduced, thereby reducing the powerconsumption of the terminal device.

Manner 3: When the scrambling identifier is a first scramblingidentifier, the terminal device starts or restarts the timer.

The first scrambling identifier is any one or a combination of a cellradio network temporary identifier C-RNTI, a configured scheduling radionetwork temporary identifier CS-RNTI, a paging radio network temporaryidentifier P-RNTI, and a system information radio network temporaryidentifier SI-RNTI.

It should be noted that, the first scrambling identifier may be any oneor a combination of the foregoing four radio network temporaryidentifiers. To be specific, any one of the foregoing four radio networktemporary identifiers may be selected to scramble the first message, orany two or three of the foregoing four radio network temporaryidentifiers may be selected to scramble the first message. Certainly,alternatively, the foregoing four radio network temporary identifiersmay all be selected to scramble the first message.

Similarly, in the manner 3, after receiving the first message, theterminal device determines the scrambling identifier used to scramblethe first message. If the scrambling identifier is the first scramblingidentifier, it indicates that the terminal device may start or restartthe timer. In this case, the terminal device starts or restarts thetimer based on the scrambling identifier. This resolves a problem thatthe terminal device cannot correctly switch to the default downlink BWPand power consumption of the terminal device cannot be reduced, therebyreducing the power consumption of the terminal device.

According to the timer processing method provided in this embodiment ofthe present invention, during determining of whether to start or restarta timer, the terminal device receives the first message sent by thenetwork device. If the active downlink bandwidth part BWP of theterminal device is not the default downlink BWP, the terminal devicestarts or restarts a timer based on the scrambling identifier of thefirst message, wherein the timer is a timer used by the terminal deviceto switch from the active downlink BWP to the default downlink BWP, orthe timer is a timer used by the terminal device to activate the defaultdownlink BWP and deactivate the active downlink BWP. If the active BWPpair of the terminal device is not the default BWP pair, the terminaldevice starts or restarts a timer based on the scrambling identifier ofthe first message, wherein the timer is a timer used by the terminaldevice to switch from the active BWP pair to the default BWP pair, orthe timer is a timer used by the terminal device to activate the defaultBWP pair and deactivate the active BWP pair. This resolves a problemthat the terminal device cannot correctly switch to the default downlinkBWP and power consumption of the terminal device cannot be reduced,thereby reducing the power consumption of the terminal device.

The embodiment shown in FIG. 5 describes in detail the solution abouthow the terminal device determines, based on the scrambling identifierof the first message, whether to start or restart a timer. The followingdescribes in detail another possible implementation in which theterminal device may determine, based on a carrier index of the firstmessage, whether to start or restart a timer. For example, the timerprocessing method is applicable to a carrier aggregation scenario. FIG.6 is a schematic diagram of another timer processing method according toan embodiment of the present invention. The timer processing method mayinclude the following steps.

S601: A terminal device receives a first message sent by a networkdevice.

The first message indicates a downlink assignment or an uplink grant, orthe first message is used to indicate bandwidth part BWP switching.

It should also be noted that, the first message may be a message such asdownlink control information carried on a PDCCH. Receiving the firstmessage may be understood as receiving the PDCCH, or receiving thedownlink control information, or receiving the downlink controlinformation carried on the PDCCH, or receiving the downlink controlinformation sent by using the PDCCH. In a paired spectrum scenario, thefirst message indicates a downlink assignment, or the first messageindicates BWP switching and a downlink BWP that is switched to is not adefault downlink BWP. In an unpaired spectrum scenario, because anuplink BWP and a downlink BWP appear in pairs, that is, a pair of uplinkand downlink BWPs are both switched during BWP switching, a default BWPmay be considered as including a pair of uplink and downlink BWPs. Inthis case, the first message indicates a downlink assignment or anuplink grant (uplink grant), or the first message indicates BWPswitching and a BWP pair that is switched to is not a default BWP pair.

S602: The terminal device starts or restarts a timer based on a carrierindex of the first message.

The timer is a timer used by the terminal device to switch from anactive downlink BWP to a default downlink BWP, or the timer is a timerused by the terminal device to activate a default downlink BWP anddeactivate an active downlink BWP, or the timer is a timer used by theterminal device to switch from an active BWP pair to the default BWPpair, or the timer is a timer used by the terminal device to activatethe default BWP pair and deactivate an active BWP pair.

It should be noted that, the carrier index of the first message hereinmay be understood as a carrier index in the first message, or a carrierindex indicated by the first message, or a carrier index included by thefirst message, or certainly, a carrier index carried by the firstmessage.

The paired spectrum scenario and the unpaired spectrum scenario aredifferent, and therefore timers started or restarted based on thecarrier index of the first message are also different. A detaileddescription is as follows.

In one scenario, namely, the paired spectrum scenario, if the activedownlink BWP of the terminal device is not the default downlink BWP andthe active downlink BWP of the terminal device is a downlink BWP of acarrier or a serving cell indicated by the carrier index, the timer is atimer of the carrier or the serving cell.

The timer is a timer used by the terminal device to switch from theactive downlink BWP to the default downlink BWP, or the timer is a timerused by the terminal device to activate the default downlink BWP anddeactivate the active downlink BWP. The following two possibilities maybe included:

Possibility 1: When the first message indicates a downlink assignmentand does not indicate BWP switching, it may be considered that theactive downlink BWP of the terminal device is a downlink BWP used forreceiving the first message, and the timer is a timer associated withthe downlink BWP used by the terminal device for receiving the firstmessage.

Possibility 2: When the first message indicates BWP switching and adownlink BWP that is switched to is not the default downlink BWP, it maybe considered that the active downlink BWP of the terminal device is thedownlink BWP that is switched to, and the timer is a timer associatedwith the downlink BWP that the terminal device is switched to. Forexample, the terminal device has two timers, which are a timer 1 and atimer 2, and the timer 1 is associated with a downlink BWP 1 and thetimer 2 is associated with a downlink BWP 2. After the terminal devicereceives a first message used to indicate switching from the currentactive downlink BWP 1 to the downlink BWP 2 that is not the defaultdownlink BWP, the terminal device needs to switch from the currentdownlink BWP 1 to the downlink BWP 2. When the terminal devicedetermines to deactivate the active downlink BWP 1, the terminal devicestops the timer associated with the to-be-deactivated downlink BWP 1, tobe specific, when the terminal device determines to activate thedownlink BWP 2 and deactivate the downlink BWP 1, correspondingly, theterminal device needs to start or restart the timer 2 associated withthe to-be-activated downlink BWP 2 and stops the timer 1 associated withthe to-be-deactivated downlink BWP 1. It should be noted that, in thisembodiment of this application, the method may further include: When theterminal device determines to deactivate the active downlink BWP, theterminal device stops the timer associated with the to-be-deactivateddownlink BWP; or when the terminal device determines to deactivate theactive BWP pair, the terminal device stops the timer associated with theto-be-deactivated BWP pair. The terminal device determines, based on thefirst message, to deactivate the active downlink BWP, and stops thetimer associated with the to-be-deactivated downlink BWP. In addition,when determining that the timer expires, the terminal device determinesto deactivate the active downlink BWP and stops the timer associatedwith the to-be-deactivated downlink BWP.

In the paired spectrum scenario, if the first message indicates adownlink assignment and does not indicate BWP switching, it may beconsidered that the active downlink BWP of the terminal device is adownlink BWP used for receiving the first message; or if the firstmessage indicates bandwidth part BWP switching, it may be consideredthat the active downlink BWP of the terminal device is a BWP that isswitched to. Alternatively, it may be considered that the activedownlink BWP of the terminal device is a BWP indicated by the firstmessage, for example, an active downlink BWP indicated in the downlinkcontrol information.

In the paired spectrum scenario, if the active downlink bandwidth partBWP of the terminal device is not the default downlink BWP, and theactive downlink BWP of the terminal device is a downlink BWP of acarrier or a serving cell indicated by the carrier index, or the activedownlink BWP of the terminal device is a downlink BWP of a carrier or aserving cell with data transmitted, the timer is a timer of the carrieror the serving cell indicated by the carrier index. For example, withcross-carrier scheduling in the carrier aggregation scenario, thecarrier or the serving cell indicated by the carrier index is differentfrom a carrier or a serving cell used for receiving the first message.The terminal device receives the first message on a carrier 1 or in aserving cell 1, and the carrier or the serving cell indicated by thecarrier index of the first message is a carrier 2 or a serving cell 2.If the downlink BWP of the carrier or the serving cell indicated by thecarrier index is not the default downlink BWP, the timer is the timer ofthe carrier or the serving cell indicated by the carrier index, namely,a timer of the carrier 2 or the serving cell 2.

Optionally, further, if the active downlink BWP of the terminal deviceis not the default downlink BWP and the active downlink BWP of theterminal device is a downlink BWP of the carrier or the serving cellused for receiving the first message, the timer is a timer of thecarrier or the serving cell used for receiving the first message. Forexample, with cross-carrier scheduling in the carrier aggregationscenario, the carrier or the serving cell indicated by the carrier indexis different from a carrier or a serving cell used for receiving thefirst message. The terminal device receives the first message on acarrier 1 or in a serving cell 1, and the carrier or the serving cellindicated by the carrier index of the first message is a carrier 2 or aserving cell 2. If the downlink BWP of the carrier or the serving cellindicated by the carrier index is not the default downlink BWP, thetimer is the timer of the carrier or the serving cell indicated by thecarrier index, namely, a timer of the carrier 2 or the serving cell 2.If the downlink BWP of the carrier or the serving cell used forreceiving the first message is not the default downlink BWP, the timeris the timer of the carrier or the serving cell used for receiving thefirst message, namely, a timer of the carrier 1 or the serving cell 1.In other words, when the foregoing conditions are met, started orrestarted timers include the timer of the carrier or the serving cellindicated by the carrier index and the timer of the carrier or theserving cell used for receiving the first message. This resolves aproblem that the terminal device cannot correctly switch to the defaultdownlink BWP and power consumption of the terminal device cannot bereduced, thereby reducing the power consumption of the terminal device.

In another scenario, namely, the unpaired spectrum scenario, if theactive BWP pair of the terminal device is not the default BWP pair andthe active BWP pair of the terminal device is a BWP pair of a carrier ora serving cell indicated by the carrier index, the timer is a timer ofthe carrier or the serving cell.

The timer is a timer used by the terminal device to switch from theactive BWP pair to the default BWP pair, or the timer is a timer used bythe terminal device to activate the default BWP pair and deactivate theactive BWP pair. The following two possibilities may be included:

Possibility 1: When the first message indicates a downlink assignment oran uplink grant and does not indicate BWP switching, it may beconsidered that the active downlink BWP of the terminal device is adownlink BWP used for receiving the first message, and the timer is atimer associated with a BWP pair used by the terminal device forreceiving the first message, or the timer is a timer associated with aBWP pair corresponding to the downlink BWP used by the terminal devicefor receiving the first message.

Possibility 2: When the first message indicates BWP switching and a BWPpair that is switched to is not the default BWP pair, it may beconsidered that the active BWP pair of the terminal device is the BWPpair that is switched to, and the timer is a timer associated with theBWP pair that the terminal device is switched to. For example, theterminal device has two timers, which are a timer 3 and a timer 4, andthe timer 3 is associated with a BWP 3 pair and the timer 4 isassociated with a BWP 4 pair. After the terminal device receives a firstmessage used to indicate switching from the current active BWP 3 pair tothe BWP 4 pair that is not the default BWP pair, the terminal deviceneeds to switch from the current BWP 3 pair to the BWP 4 pair. When theterminal device determines to deactivate the active BWP 3 pair, theterminal device stops the timer associated with the to-be-deactivatedBWP 3 pair, to be specific, when the terminal device determines toactivate the BWP 4 pair and deactivate the BWP 3 pair, correspondingly,the terminal device needs to start or restart the timer 4 associatedwith the to-be-activated BWP 4 pair and stops the timer 3 associatedwith the to-be-deactivated BWP 3 pair. It should be noted that, in thisembodiment of this application, the method may further include: When theterminal device determines to deactivate the active downlink BWP, theterminal device stops the timer associated with the to-be-deactivateddownlink BWP; or when the terminal device determines to deactivate theactive BWP pair, the terminal device stops the timer associated with theto-be-deactivated BWP pair. The terminal device determines, based on thefirst message, to deactivate the active BWP pair, and stops the timerassociated with the to-be-deactivated BWP pair. In addition, whendetermining that the timer expires, the terminal device determines todeactivate the active BWP pair and stops the timer associated with theto-be-deactivated BWP pair.

In the unpaired spectrum scenario, if the first message indicates adownlink assignment or an uplink grant and does not indicate BWPswitching, it may be considered that the active BWP pair of the terminaldevice is a BWP pair that is corresponding to a downlink BWP used forreceiving the first message or a BWP pair to which a downlink BWP usedfor receiving the first message belongs; or if the first messageindicates bandwidth part BWP switching, it may be considered that theactive BWP pair of the terminal device is a BWP pair that is switchedto. Alternatively, it may be considered that the active BWP pair of theterminal device is a BWP pair indicated by the first message, forexample, an active BWP pair indicated in the downlink controlinformation. Alternatively, it may be considered that the active BWPpair of the terminal device is a BWP pair that is corresponding to adownlink BWP indicated by the first message or a BWP pair to which adownlink BWP indicated by the first message belongs, for example, anactive BWP pair that is corresponding to a downlink BWP indicated in thedownlink control information or an active BWP pair to which a downlinkBWP indicated in the downlink control information belongs.

In the unpaired spectrum scenario, if the active bandwidth part BWP pairof the terminal device is not the default BWP pair, and the active BWPpair of the terminal device is a BWP pair of a carrier or a serving cellindicated by the carrier index, or the active BWP pair of the terminaldevice is a BWP pair of a carrier or a serving cell with datatransmitted, the timer is a timer of the carrier or the serving cellindicated by the carrier index. For example, with cross-carrierscheduling in the carrier aggregation scenario, the carrier or theserving cell indicated by the carrier index is different from a carrieror a serving cell used for receiving the first message. The terminaldevice receives the first message on a carrier 1 or in a serving cell 1,and the carrier or the serving cell indicated by the carrier index ofthe first message is a carrier 2 or a serving cell 2. If the BWP pair ofthe carrier or the serving cell indicated by the carrier index is notthe default BWP pair, the timer is the timer of the carrier or theserving cell indicated by the carrier index, namely, a timer of thecarrier 2 or the serving cell 2.

Optionally, further, if the active BWP pair of the terminal device isnot the default BWP pair and the active BWP pair of the terminal deviceis a BWP pair of the carrier or the serving cell used for receiving thefirst message, the timer is a timer of the carrier or the serving cellused for receiving the first message. For example, with cross-carrierscheduling in the carrier aggregation scenario, the carrier or theserving cell indicated by the carrier index is different from a carrieror a serving cell used for receiving the first message. The terminaldevice receives the first message on a carrier 1 or in a serving cell 1,and the carrier or the serving cell indicated by the carrier index ofthe first message is a carrier 2 or a serving cell 2. If the BWP pair ofthe carrier or the serving cell indicated by the carrier index is notthe default BWP pair, the timer is the timer of the carrier or theserving cell indicated by the carrier index, namely, a timer of thecarrier 2 or the serving cell 2. If the BWP pair of the carrier or theserving cell used for receiving the first message is not the default BWPpair, the timer is the timer of the carrier or the serving cell used forreceiving the first message, namely, a timer of the carrier 1 or theserving cell 1. In other words, when the foregoing conditions are met,started or restarted timers include the timer of the carrier or theserving cell indicated by the carrier index and the timer of the carrieror the serving cell used for receiving the first message. This resolvesa problem that the terminal device cannot correctly switch to thedefault downlink BWP and power consumption of the terminal device cannotbe reduced, thereby reducing the power consumption of the terminaldevice.

According to the timer processing method provided in this embodiment ofthe present invention, during determining of whether to start or restarta timer, the terminal device receives the first message sent by thenetwork device. The terminal device starts or restarts the timer basedon the carrier index of the first message, wherein the timer is a timerused by the terminal device to switch from the active downlink BWP tothe default downlink BWP, or the timer is a timer used by the terminaldevice to activate the default downlink BWP and deactivate the activedownlink BWP, or the timer is a timer used by the terminal device toswitch from the active BWP pair to the default BWP pair, or the timer isa timer used by the terminal device to activate the default BWP pair anddeactivate the active BWP pair. This resolves a problem that theterminal device cannot correctly switch to the default downlink BWP andpower consumption of the terminal device cannot be reduced, therebyreducing the power consumption of the terminal device.

The embodiment shown in FIG. 6 describes in detail the solution abouthow the terminal device determines, based on the carrier index of thefirst message, whether to start or restart a timer. In addition, a timeris started or restarted only when a PDCCH is received in the prior art.Therefore, there is no timer restart condition in a non-dynamicscheduling process, and the terminal device may fall back to a defaultBWP in the non-dynamic scheduling process. Consequently, current datatransmission of the terminal device is affected. Therefore, in anembodiment of the present invention, a description about how to start orrestart a timer in the non-dynamic scheduling process is added. FIG. 7is a schematic diagram of another timer processing method according toan embodiment of the present invention. The timer processing method mayinclude the following steps.

S701: A terminal device determines that at least one configured resourceexists.

It should also be noted that, in a paired spectrum scenario, an activedownlink BWP of the terminal device is not a default downlink BWP. In anunpaired spectrum scenario, because an uplink BWP and a downlink BWPappear in pairs, that is, a pair of uplink and downlink BWPs are bothswitched during BWP switching, a default BWP may be considered asincluding a pair of uplink and downlink BWPs. In this case, an activeBWP pair of the terminal device is not a default BWP pair.

It should be noted that, that at least one configured resource existsherein may be understood as the following: there is at least oneconfigured resource, or at least one configured resource appears, orcertainly, at least one configured resource occurs, or the like.

As there are different scenarios, methods for starting or restarting, bythe terminal device, a timer based on the at least one configuredresource that exists are different, and respectively correspond to S402and S403.

S702: If an active downlink BWP of the terminal device is not a defaultdownlink BWP, the terminal device starts or restarts, based on the atleast one configured resource that exists, a timer associated with theactive downlink BWP.

The timer is a timer used by the terminal device to switch from theactive downlink BWP to the default downlink BWP, or the timer is a timerused by the terminal device to activate the default downlink BWP anddeactivate the active downlink BWP.

It should be noted that, in the paired spectrum scenario in which atimer is associated with a BWP, if the active downlink BWP of theterminal device is not the default downlink BWP, when the terminaldevice starts or restarts the timer based on the scrambling identifierof the first message, the timer is the timer associated with the activedownlink BWP of the terminal device. The following two possibilities maybe included:

Possibility 1: When the first message indicates a downlink assignmentand does not indicate BWP switching, it may be considered that theactive downlink BWP of the terminal device is a downlink BWP used forreceiving the first message, and the timer is a timer associated withthe downlink BWP used by the terminal device for receiving the firstmessage.

Possibility 2: When the first message indicates BWP switching and adownlink BWP that is switched to is not the default downlink BWP, it maybe considered that the active downlink BWP of the terminal device is thedownlink BWP that is switched to, and the timer is a timer associatedwith the downlink BWP that the terminal device is switched to. Forexample, the terminal device has two timers, which are a timer 1 and atimer 2, and the timer 1 is associated with a downlink BWP 1 and thetimer 2 is associated with a downlink BWP 2. After the terminal devicereceives a first message used to indicate switching from the currentactive downlink BWP 1 to the downlink BWP 2 that is not the defaultdownlink BWP, the terminal device needs to switch from the currentdownlink BWP 1 to the downlink BWP 2. When the terminal devicedetermines to deactivate the active downlink BWP 1, the terminal devicestops the timer associated with the to-be-deactivated downlink BWP 1, tobe specific, when the terminal device determines to activate thedownlink BWP 2 and deactivate the downlink BWP 1, correspondingly, theterminal device needs to start or restart the timer 2 associated withthe to-be-activated downlink BWP 2 and stops the timer 1 associated withthe to-be-deactivated downlink BWP 1. It should be noted that, in thisembodiment of this application, the method may further include: When theterminal device determines to deactivate the active downlink BWP, theterminal device stops the timer associated with the to-be-deactivateddownlink BWP; or when the terminal device determines to deactivate theactive BWP pair, the terminal device stops the timer associated with theto-be-deactivated BWP pair. The terminal device determines, based on thefirst message, to deactivate the active downlink BWP, and stops thetimer associated with the to-be-deactivated downlink BWP. In addition,when determining that the timer expires, the terminal device determinesto deactivate the active downlink BWP and stops the timer associatedwith the to-be-deactivated downlink BWP.

In the solution shown in S702, in the paired spectrum scenario, if theactive downlink BWP of the terminal device is not the default downlinkBWP and the configured resource is a downlink resource, the terminaldevice may start or restart, based on the at least one configuredresource that exists, the timer associated with the active downlink BWP.

Optionally, that the terminal device starts or restarts a timer based onthe at least one configured resource that exists in S702 may include thefollowing possible manners:

Manner 1: When the terminal device determines that the at least oneconfigured resource exists, the terminal device starts or restarts thetimer associated with the active downlink BWP.

In the manner 1, for example, with non-dynamic scheduling, for example,downlink semi-persistent scheduling (Semi-Persistent Scheduling, SPS),when the terminal device determines that at least one configureddownlink resource exists, that is, at least one configured downlinkassignment (downlink assignment) exists, the terminal device starts orrestarts the timer, wherein the timer is a timer used by the terminaldevice to switch from the active downlink BWP to the default downlinkBWP, or the timer is a timer used by the terminal device to activate thedefault downlink BWP and deactivate the active downlink BWP. This avoidsa prior-art problem that the terminal device may fall back to a defaultBWP in a non-dynamic scheduling process because a timer is started orrestarted only when a PDCCH is received, thereby avoiding impact oncurrent data transmission of the terminal device. It should be notedthat, the at least one configured resource is at least one configuredresource on the active downlink BWP of the terminal device.

The manner 1 describes direct timer start or restart performed when atleast one configured resource exists. Certainly, whether data istransmitted on the configured resource may further be determined, todetermine whether to start or restart the timer, as described in amanner 2 below:

Manner 2: When determining that there is data transmitted on theconfigured resource, the terminal device starts or restarts the timerassociated with the active downlink BWP.

In the manner 2, the terminal device does not start or restart the timerafter determining that at least one configured resource exists. Instead,the terminal device further determines whether data is transmitted onthe configured resource. For example, with non-dynamic scheduling, forexample, downlink semi-persistent scheduling (Semi-PersistentScheduling, SPS), when the terminal device determines that downlink datais transmitted on at least one configured downlink resource, that is,downlink data is transmitted on at least one configured downlinkassignment (downlink assignment), the terminal device starts or restartsthe timer, wherein the timer is a timer used by the terminal device toswitch from the active downlink BWP to the default downlink BWP, or thetimer is a timer used by the terminal device to activate the defaultdownlink BWP and deactivate the active downlink BWP. This avoids aprior-art problem that the terminal device may fall back to a defaultBWP in a non-dynamic scheduling process because a timer is started orrestarted only when a PDCCH is received, thereby avoiding impact oncurrent data transmission of the terminal device. It should be notedthat, the data transmission is data transmission on the active downlinkBWP of the terminal device.

S703: If an active BWP pair of the terminal device is not a default BWPpair, the terminal device starts or restarts a timer based on the atleast one configured resource that exists.

The timer is a timer used by the terminal device to switch from theactive BWP pair to the default BWP pair, or the timer is a timer used bythe terminal device to activate the default BWP pair and deactivate theactive BWP pair.

It should be noted that, in the unpaired spectrum scenario in which atimer is associated with a BWP, if the active BWP pair of the terminaldevice is not the default BWP pair, when the terminal device starts orrestarts the timer based on the scrambling identifier of the firstmessage, the timer is the timer associated with the active BWP pair ofthe terminal device. The following two possibilities may be included:

Possibility 1: When the first message indicates a downlink assignment oran uplink grant and does not indicate BWP switching, it may beconsidered that the active downlink BWP of the terminal device is adownlink BWP used for receiving the first message, and the timer is atimer associated with a BWP pair used by the terminal device forreceiving the first message, or the timer is a timer associated with aBWP pair corresponding to the downlink BWP used by the terminal devicefor receiving the first message.

Possibility 2: When the first message indicates BWP switching and a BWPpair that is switched to is not the default BWP pair, it may beconsidered that the active BWP pair of the terminal device is the BWPpair that is switched to, and the timer is a timer associated with theBWP pair that the terminal device is switched to. For example, theterminal device has two timers, which are a timer 3 and a timer 4, andthe timer 3 is associated with a BWP 3 pair and the timer 4 isassociated with a BWP 4 pair. After the terminal device receives a firstmessage used to indicate switching from the current active BWP 3 pair tothe BWP 4 pair that is not the default BWP pair, the terminal deviceneeds to switch from the current BWP 3 pair to the BWP 4 pair. When theterminal device determines to deactivate the active BWP 3 pair, theterminal device stops the timer associated with the to-be-deactivatedBWP 3 pair, to be specific, when the terminal device determines toactivate the BWP 4 pair and deactivate the BWP 3 pair, correspondingly,the terminal device needs to start or restart the timer 4 associatedwith the to-be-activated BWP 4 pair and stops the timer 3 associatedwith the to-be-deactivated BWP 3 pair. It should be noted that, in thisembodiment of this application, the method may further include: When theterminal device determines to deactivate the active downlink BWP, theterminal device stops the timer associated with the to-be-deactivateddownlink BWP; or when the terminal device determines to deactivate theactive BWP pair, the terminal device stops the timer associated with theto-be-deactivated BWP pair. The terminal device determines, based on thefirst message, to deactivate the active BWP pair, and stops the timerassociated with the to-be-deactivated BWP pair. In addition, whendetermining that the timer expires, the terminal device determines todeactivate the active BWP pair and stops the timer associated with theto-be-deactivated BWP pair.

In the solution shown in S703, in the unpaired spectrum scenario, if theactive BWP pair of the terminal device is not the default BWP pair andthe configured resource is a downlink resource or an uplink resource,the terminal device may start or restart, based on the at least oneconfigured resource that exists, the timer associated with the activeBWP pair.

Optionally, that the terminal device starts or restarts, based on the atleast one configured resource that exists, a timer associated with theactive BWP pair in S703 may include the following possible manners:

Manner 1: When the terminal device determines that the at least oneconfigured resource exists, the terminal device starts or restarts thetimer associated with the active BWP pair.

In the manner 1, for example, with non-dynamic scheduling, for example,downlink semi-persistent scheduling (Semi-Persistent Scheduling, SPS),grant free (Grant Free, GF) scheduling, or uplink semi-persistentscheduling, wherein the grant free (Grant Free, GF) scheduling is alsoreferred to as a configured grant type 1 (configured grant Type 1) andthe uplink semi-persistent scheduling is also referred to as aconfigured grant type 2 (configured grant Type 2), when the terminaldevice determines that at least one configured downlink resource orconfigured uplink resource exists, that is, at least one configureddownlink assignment (downlink assignment) exists or at least oneconfigured uplink grant (uplink grant) exists, the terminal devicestarts or restarts the timer, wherein the timer is a timer used by theterminal device to switch from the active downlink BWP to the defaultdownlink BWP, or the timer is a timer used by the terminal device toactivate the default BWP pair and deactivate the active BWP pair. Thisavoids a prior-art problem that the terminal device may fall back to adefault BWP in a non-dynamic scheduling process because a timer isstarted or restarted only when a PDCCH is received, thereby avoidingimpact on current data transmission of the terminal device. It should benoted that, the at least one configured resource is at least oneconfigured resource on the active BWP pair of the terminal device.

The manner 1 describes direct timer start or restart performed when atleast one configured resource exists. Certainly, whether data istransmitted on the configured resource may further be determined, todetermine whether to start or restart the timer, as described in amanner 2 below:

Manner 2: When determining that there is date transmitted on theconfigured resource, the terminal device starts or restarts the timerassociated with the active BWP pair.

In the manner 2, the terminal device does not start or restart the timerafter determining that at least one configured resource exists. Instead,the terminal device further determines whether data is transmitted onthe configured resource. For example, with non-dynamic scheduling, forexample, downlink semi-persistent scheduling (Semi-PersistentScheduling, SPS), grant free (Grant Free, GF) scheduling, or uplinksemi-persistent scheduling, wherein the grant free (Grant Free, GF)scheduling is also referred to as a configured grant type 1 (configuredgrant Type 1) and the uplink semi-persistent scheduling is also referredto as a configured grant type 2 (configured grant Type 2), when theterminal device determines that downlink data is transmitted on at leastone configured downlink resource, that is, downlink data is transmittedon at least one configured downlink assignment (downlink assignment),the terminal device starts or restarts the timer; or when the terminaldevice determines that uplink data is transmitted on at least oneconfigured uplink resource, that is, uplink data is transmitted on atleast one configured uplink grant (uplink grant), the terminal devicestarts or restarts the timer, wherein the timer is a timer used by theterminal device to switch from the active BWP pair to the default BWPpair, or the timer is a timer used by the terminal device to activatethe default downlink BWP and deactivate the active downlink BWP. Thisavoids a prior-art problem that the terminal device may fall back to adefault BWP in a non-dynamic scheduling process because a timer isstarted or restarted only when a PDCCH is received, thereby avoidingimpact on current data transmission of the terminal device. It should benoted that, the data transmission is data transmission on the active BWPpair of the terminal device.

It should be noted that, in one scheduling process, only either S702 orS703 is executed after S701 is executed, in other words, S702 and S703are not synchronously executed.

According to the timer processing method provided in this embodiment ofthe present invention, during determining of whether to start or restarta timer, the terminal device determines that at least one configuredresource exists or determines that data is transmitted on the at leastone configured resource. If the active downlink BWP of the terminaldevice is not the default downlink BWP, the terminal device starts orrestarts the timer based on the at least one configured resource thatexists or the terminal device starts or restarts the timer based on afact that data is transmitted on the at least one configured resource,wherein the timer is a timer used by the terminal device to switch fromthe active downlink BWP to the default downlink BWP, or the timer is atimer used by the terminal device to activate the default downlink BWPand deactivate the active downlink BWP; if the active BWP pair of theterminal device is not the default BWP pair, the terminal device startsor restarts the timer based on the at least one configured resource thatexists or the terminal device starts or restarts the timer based on afact that data is transmitted on the at least one configured resource,wherein the timer is a timer used by the terminal device to switch fromthe active BWP pair to the default BWP pair, or the timer is a timerused by the terminal device to activate the default BWP pair anddeactivate the active BWP pair. This resolves a problem that theterminal device falls back to a default BWP in a non-dynamic schedulingprocess, thereby avoiding impact on current data transmission of theterminal device.

It should be noted that, the timer in the embodiments shown in FIG. 5 toFIG. 7 may further be another type of timer. The another type of timermay be a timer used by the terminal device to deactivate the activedownlink BWP, or the another type of timer may be used by the terminaldevice to deactivate the active BWP pair of the terminal device. Inaddition, it should be noted that, the downlink BWP in the pairedspectrum scenario may represent a downlink BWP in a BWP pair, and mayalso represent an uplink BWP paired with the downlink BWP, in otherwords, the downlink BWP may be understood as a BWP pair corresponding tothe downlink BWP.

An embodiment of the present invention provides another timer processingmethod. The method is specifically as follows.

A terminal device receives an instruction message sent by a networkdevice, wherein the instruction message instructs the terminal device toactivate at least one secondary serving cell.

The terminal device starts or restarts a timer associated with thesecondary serving cell.

In a paired spectrum scenario, the timer is a timer used by the terminaldevice to switch from an active downlink bandwidth part BWP to a defaultdownlink BWP, or the timer is a timer used by the terminal device toactivate a default downlink BWP and deactivate an active downlink BWP.In an unpaired spectrum scenario, the timer is a timer used by theterminal device to switch from an active BWP pair to a default BWP pair,or the timer is a timer used by the terminal device to activate adefault BWP pair and deactivate an active BWP pair.

Optionally, the secondary serving cell is in an inactive state.

Optionally, before the terminal device receives the instruction messagesent by the network device, the method further includes:

The terminal device receives a radio resource control RRC message sentby the network device, wherein the RRC message includes instructioninformation, and the instruction information instructs to add or modifythe at least one secondary serving cell. In the paired spectrumscenario, the RRC message further includes a first downlink BWP of thesecondary serving cell, the first downlink BWP is a downlink BWP that isfirst activated when the secondary serving cell is activated, and thefirst downlink BWP is not a default downlink BWP. In the unpairedspectrum scenario, the RRC message further includes a first BWP pair ofthe secondary serving cell, the first BWP pair is a BWP pair that isfirst activated when the secondary serving cell is activated, and thefirst BWP pair is not a default downlink BWP pair.

In the paired spectrum scenario, the timer is a timer associated withthe first downlink BWP, or the timer is a timer associated with acurrent active downlink BWP, and the current active downlink BWP may bethe first downlink BWP. That the terminal device starts or restarts atimer associated with the secondary serving cell may be understood asthat the terminal device starts or restarts the timer associated withthe first downlink BWP associated with the secondary serving cell. Inthe unpaired spectrum scenario, the timer is a timer associated with thefirst BWP pair, or the timer is a timer associated with a current activeBWP pair, and the current active BWP pair may be a first downlink BWP.That the terminal device starts or restarts a timer associated with thesecondary serving cell may be understood as that the terminal devicestarts or restarts the timer associated with the first BWP pairassociated with the secondary serving cell.

An embodiment of the present invention provides another timer processingmethod. The method is specifically as follows.

A terminal device receives an instruction message sent by a networkdevice, wherein the instruction message instructs the terminal device todeactivate at least one secondary serving cell, and a timer associatedwith the secondary serving cell is in a running state.

In a paired spectrum scenario, the timer is a timer used by the terminaldevice to switch from an active downlink bandwidth part BWP to a defaultdownlink BWP, or the timer is a timer used by the terminal device toactivate a default downlink BWP and deactivate an active downlink BWP.In an unpaired spectrum scenario, the timer is a timer used by theterminal device to switch from an active BWP pair to a default BWP pair,or the timer is a timer used by the terminal device to activate adefault BWP pair and deactivate an active BWP pair.

The terminal device stops or resets the timer associated with thesecondary serving cell, or the terminal device stops and resets thetimer associated with the secondary serving cell.

In the paired spectrum scenario, the timer is a timer associated withthe active downlink BWP of the terminal device, or the timer is a timerassociated with an active downlink BWP of the terminal device in thesecondary serving cell. That the terminal device stops or resets thetimer associated with the secondary serving cell may be understood asthat the terminal device stops or resets the timer associated with theactive downlink BWP of the secondary serving cell, or that the terminaldevice stops or resets the timer associated with the secondary servingcell may be understood as that the terminal device stops or resets atimer associated with any one or all of active downlink BWPs of thesecondary serving cell. In the unpaired spectrum scenario, the timer isa timer associated with the active BWP pair of the terminal device, orthe timer is a timer associated with an active BWP pair of the terminaldevice in the secondary serving cell. That the terminal device stops orresets the timer associated with the secondary serving cell may beunderstood as that the terminal device stops or resets the timerassociated with the active BWP pair of the secondary serving cell, orthat the terminal device stops or resets the timer associated with thesecondary serving cell may be understood as that the terminal devicestops or resets a timer associated with any one or all of active BWPpairs of the secondary serving cell.

An embodiment of the present invention provides another timer processingmethod. The method is specifically as follows.

A terminal device determines that a secondary serving cell deactivationtimer of a secondary serving cell expires, wherein a timer associatedwith the secondary serving cell is in a running state.

In a paired spectrum scenario, the timer is a timer used by the terminaldevice to switch from an active downlink bandwidth part BWP to a defaultdownlink BWP, or the timer is a timer used by the terminal device toactivate a default downlink BWP and deactivate an active downlink BWP.In an unpaired spectrum scenario, the timer is a timer used by theterminal device to switch from an active BWP pair to a default BWP pair,or the timer is a timer used by the terminal device to activate adefault BWP pair and deactivate an active BWP pair.

The terminal device stops or resets the timer associated with thesecondary serving cell, or the terminal device stops and resets thetimer associated with the secondary serving cell.

In the paired spectrum scenario, the timer is a timer associated withthe active downlink BWP of the terminal device, or the timer is a timerassociated with an active downlink BWP of the terminal device in thesecondary serving cell. That the terminal device stops or resets thetimer associated with the secondary serving cell may be understood asthat the terminal device stops or resets the timer associated with theactive downlink BWP of the secondary serving cell, or that the terminaldevice stops or resets the timer associated with the secondary servingcell may be understood as that the terminal device stops or resets atimer associated with any one or all of active downlink BWPs of thesecondary serving cell. In the unpaired spectrum scenario, the timer isa timer associated with the active BWP pair of the terminal device, orthe timer is a timer associated with an active BWP pair of the terminaldevice in the secondary serving cell. That the terminal device stops orresets the timer associated with the secondary serving cell may beunderstood as that the terminal device stops or resets the timerassociated with the active BWP pair of the secondary serving cell, orthat the terminal device stops or resets the timer associated with thesecondary serving cell may be understood as that the terminal devicestops or resets a timer associated with any one or all of active BWPpairs of the secondary serving cell.

FIG. 8 is a schematic structural diagram of a terminal device 80according to an embodiment of this application. As shown in FIG. 8, theterminal device 80 may include a receiving unit 801 and a processingunit 802.

The receiving unit 801 is configured to receive a first message sent bya network device, wherein the first message is used to indicate adownlink assignment or an uplink grant, or the first message is used toindicate bandwidth part BWP switching.

The processing unit 802 is configured to: if an active downlinkbandwidth part BWP of the terminal device 80 is not a default downlinkBWP, start or restart a timer based on a scrambling identifier of thefirst message, wherein the timer is a timer used by the terminal device80 to switch from the active downlink BWP to the default downlink BWP,or the timer is a timer used by the terminal device 80 to activate thedefault downlink BWP and deactivate the active downlink BWP.

The processing unit 802 is further configured to: if an active BWP pairof the terminal device 80 is not a default BWP pair, start or restart atimer based on a scrambling identifier of the first message, wherein thetimer is a timer used by the terminal device 80 to switch from theactive BWP pair to the default BWP pair, or the timer is a timer used bythe terminal device 80 to activate the default BWP pair and deactivatethe active BWP pair.

Optionally, the processing unit 802 is specifically configured to startor restart the timer when the scrambling identifier is not a randomaccess radio network temporary identifier RA-RNTI or a temporary cellradio network temporary identifier TC-RNTI.

Optionally, the processing unit 802 is specifically configured to startor restart the timer when the scrambling identifier is a firstscrambling identifier, wherein the first scrambling identifier is anyone or a combination of a cell radio network temporary identifierC-RNTI, a configured scheduling radio network temporary identifierCS-RNTI, a paging radio network temporary identifier P-RNTI, and asystem information radio network temporary identifier SI-RNTI.

Optionally, the processing unit 802 is specifically configured to startor restart the timer when the scrambling identifier is a random accessradio network temporary identifier RA-RNTI and the terminal device 80executes non-contention-based random access.

Optionally, the terminal device 80 may further include:

a maintaining unit 803, configured to, when the scrambling identifier isan RA-RNTI and the terminal device executes contention-based randomaccess, control the timer to maintain an original state.

Optionally, the timer is a timer associated with the active downlink BWPof the terminal device 80, or the timer is a timer associated with theactive BWP pair of the terminal device 80.

The terminal device 80 shown in this embodiment of this application mayexecute the technical solution of the timer processing method in theembodiment shown in FIG. 2 or FIG. 5. Implementation principles andtechnical effects thereof are similar, and details are not describedherein again.

FIG. 9 is a schematic structural diagram of another terminal device 90according to an embodiment of this application. As shown in FIG. 9, theterminal device 90 may include a receiving unit 901 and a processingunit 902.

The receiving unit 901 is configured to receive a first message sent bya network device, wherein the first message is used to indicate adownlink assignment or an uplink grant, or the first message is used toindicate bandwidth part BWP switching.

The processing unit 902 is configured to start or restart a timer basedon a carrier index of the first message, wherein the timer is a timerused by the terminal device 90 to switch from an active downlink BWP toa default downlink BWP, or the timer is a timer used by the terminaldevice 90 to activate a default downlink BWP and deactivate an activedownlink BWP, or the timer is a timer used by the terminal device 90 toswitch from an active BWP pair to a default BWP pair, or the timer is atimer used by the terminal device 90 to activate a default BWP pair anddeactivate an active BWP pair.

Optionally, if the active downlink BWP of the terminal device 90 is notthe default downlink BWP and the active downlink BWP of the terminaldevice 90 is a downlink BWP of a carrier or a serving cell indicated bythe carrier index, or if the active BWP pair of the terminal device 90is not the default BWP pair and the active BWP pair of the terminaldevice 90 is a BWP pair of a carrier or a serving cell indicated by thecarrier index, the timer is a timer of the carrier or the serving cell.

Optionally, if the active downlink BWP of the terminal device 90 is notthe default downlink BWP and the active downlink BWP of the terminaldevice 90 is a downlink BWP of a carrier or a serving cell used forreceiving the first message, or if the active BWP pair of the terminaldevice 90 is not the default BWP pair and the active BWP pair of theterminal device 90 is a BWP pair of a carrier or a serving cell used forreceiving the first message, the timer is a timer of the carrier or theserving cell used for receiving the first message.

Optionally, the timer is a timer associated with the active downlink BWPof the terminal device 90, or the timer is a timer associated with anactive downlink BWP of the terminal device 90 on the carrier or in theserving cell, or the timer is a timer associated with the active BWPpair of the terminal device 90, or the timer is a timer associated withan active BWP pair of the terminal device 90 on the carrier or in theserving cell.

The terminal device 90 shown in this embodiment of this application mayexecute the technical solution of the timer processing method in theembodiment shown in FIG. 3 or FIG. 6. Implementation principles andtechnical effects thereof are similar, and details are not describedherein again.

FIG. 10 is a schematic structural diagram of another terminal device 100according to an embodiment of this application. As shown in FIG. 10, theterminal device 100 may include a determining unit 1001 and a processingunit 1002.

The determining unit 1001 is configured to determine that at least oneconfigured resource exists.

The processing unit 1002 is configured to: if an active bandwidth partBWP pair of the terminal device 100 is not a default BWP pair, start orrestart a timer based on the at least one configured resource thatexists, wherein the timer is a timer used by the terminal device 100 toswitch from the active BWP pair to the default BWP pair, or the timer isa timer used by the terminal device 100 to activate the default BWP pairand deactivate the active BWP pair.

Optionally, data is transmitted on the configured resource.

Optionally, the configured resource is a downlink resource or an uplinkresource.

The processing unit 1002 is specifically configured to: start or restartthe timer when the at least one configured resource exists; or start orrestart the timer when the configured resource is a downlink resourceand downlink data is transmitted on the downlink resource; or start orrestart the timer when the configured resource is an uplink resource anduplink data is transmitted on the uplink resource.

Optionally, the timer is a timer associated with the active BWP pair ofthe terminal device 100.

The terminal device 100 shown in this embodiment of this application mayexecute the technical solution of the timer processing method in theembodiment shown in FIG. 4 or FIG. 7. Implementation principles andtechnical effects thereof are similar, and details are not describedherein again.

FIG. 11 is a schematic structural diagram of a terminal device 110according to an embodiment of this application. As shown in FIG. 11, theterminal device 110 may include a receiver 1101 and a processor 1102.

The receiver 1101 is configured to receive a first message sent by anetwork device, wherein the first message is used to indicate a downlinkassignment or an uplink grant, or the first message is used to indicatebandwidth part BWP switching.

The processor 1102 is configured to: if an active downlink BWP of theterminal device 110 is not a default downlink BWP, start or restart atimer based on a scrambling identifier of the first message, wherein thetimer is a timer used by the terminal device 110 to switch from theactive downlink BWP to the default downlink BWP, or the timer is a timerused by the terminal device 110 to activate the default downlink BWP anddeactivate the active downlink BWP; or

the processor 1102 is configured to: if an active BWP pair of theterminal device 110 is not a default BWP pair, start or restart a timerbased on a scrambling identifier of the first message, wherein the timeris a timer used by the terminal device 110 to switch from the active BWPpair to the default BWP pair, or the timer is a timer used by theterminal device 110 to activate the default BWP pair and deactivate theactive BWP pair.

Optionally, the processor 1102 is specifically configured to start orrestart the timer when the scrambling identifier is not a random accessradio network temporary identifier RA-RNTI or a temporary cell radionetwork temporary identifier TC-RNTI.

Optionally, the processor 1102 is specifically configured to start orrestart the timer when the scrambling identifier is a first scramblingidentifier, wherein the first scrambling identifier is any one or acombination of a cell radio network temporary identifier C-RNTI, aconfigured scheduling radio network temporary identifier CS-RNTI, apaging radio network temporary identifier P-RNTI, and a systeminformation radio network temporary identifier SI-RNTI.

Optionally, the processor 1102 is specifically configured to start orrestart the timer when the scrambling identifier is a random accessradio network temporary identifier RA-RNTI and the terminal device 110executes non-contention-based random access.

Optionally, the processor 1102 is further configured to, when thescrambling identifier is an RA-RNTI and the terminal device executescontention-based random access, control the timer to maintain anoriginal state.

Optionally, the timer is a timer associated with the active downlink BWPof the terminal device 110, or the timer is a timer associated with theactive BWP pair of the terminal device 110.

The terminal device 110 shown in this embodiment of this application mayexecute the technical solution of the timer processing method in theembodiment shown in FIG. 2 or FIG. 5. Implementation principles andtechnical effects thereof are similar, and details are not describedherein again.

FIG. 12 is a schematic structural diagram of another terminal device 120according to an embodiment of the present invention. As shown in FIG.12, the terminal device 120 may include a receiver 1201 and a processor1202.

The receiver 1201 is configured to receive a first message sent by anetwork device, wherein the first message is used to indicate a downlinkassignment or an uplink grant, or the first message is used to indicatebandwidth part BWP switching.

The processor 1202 is configured to start or restart a timer based on acarrier index of the first message, wherein the timer is a timer used bythe terminal device 120 to switch from an active downlink BWP to adefault downlink BWP, or the timer is a timer used by the terminaldevice 120 to activate a default downlink BWP and deactivate an activedownlink BWP, or the timer is a timer used by the terminal device 120 toswitch from an active BWP pair to a default BWP pair, or the timer is atimer used by the terminal device 120 to activate a default BWP pair anddeactivate an active BWP pair.

Optionally, if the active downlink BWP of the terminal device 120 is notthe default downlink BWP and the active downlink BWP of the terminaldevice 120 is a downlink BWP of a carrier or a serving cell indicated bythe carrier index, or if the active BWP pair of the terminal device 120is not the default BWP pair and the active BWP pair of the terminaldevice 120 is a BWP pair of a carrier or a serving cell indicated by thecarrier index, the timer is a timer of the carrier or the serving cell.

Optionally, if the active downlink BWP of the terminal device 120 is notthe default downlink BWP and the active downlink BWP of the terminaldevice 120 is a downlink BWP of a carrier or a serving cell used forreceiving the first message, or if the active BWP pair of the terminaldevice 120 is not the default BWP pair and the active BWP pair of theterminal device 120 is a BWP pair of a carrier or a serving cell usedfor receiving the first message, the timer is a timer of the carrier orthe serving cell used for receiving the first message.

Optionally, the timer is a timer associated with the active downlink BWPof the terminal device 120, or the timer is a timer associated with anactive downlink BWP of the terminal device 120 on the carrier or in theserving cell, or the timer is a timer associated with the active BWPpair of the terminal device 120, or the timer is a timer associated withan active BWP pair of the terminal device 120 on the carrier or in theserving cell.

The terminal device 120 shown in this embodiment of this application mayexecute the technical solution of the timer processing method in theembodiment shown in FIG. 3 or FIG. 6. Implementation principles andtechnical effects thereof are similar, and details are not describedherein again.

FIG. 13 is a schematic structural diagram of another terminal device 130according to an embodiment of this application. As shown in FIG. 13, theterminal device 130 may include a processor 1301.

The processor 1301 is configured to determine that at least oneconfigured resource exists.

The processor 1301 is configured to: if an active bandwidth part BWPpair of the terminal device 130 is not a default BWP pair, start orrestart a timer based on the at least one configured resource thatexists, wherein the timer is a timer used by the terminal device 130 toswitch from the active BWP pair to the default BWP pair, or the timer isa timer used by the terminal device 130 to activate the default BWP pairand deactivate the active BWP pair.

Optionally, data is transmitted on the configured resource.

Optionally, the configured resource is a downlink resource or an uplinkresource.

The processor 1301 is specifically configured to: start or restart thetimer when determining that the at least one configured resource exists;or start or restart the timer when the configured resource is a downlinkresource and downlink data is transmitted on the downlink resource; orstart or restart the timer when the configured resource is an uplinkresource and uplink data is transmitted on the uplink resource.

Optionally, the timer is a timer associated with the active BWP pair ofthe terminal device 130.

The terminal device 130 shown in this embodiment of this application mayexecute the technical solution of the timer processing method in theembodiment shown in FIG. 4 or FIG. 7. Implementation principles andtechnical effects thereof are similar, and details are not describedherein again.

FIG. 14 is a schematic structural diagram of another terminal device 140according to an embodiment of this application. As shown in FIG. 14, theterminal device 140 may include a processor 1401 and a memory 1402.

The memory 1402 is configured to store a program instruction.

The processor 1401 is configured to invoke and execute the programinstruction stored in the memory 1402, to execute the timer processingmethod shown in any one of the foregoing embodiments.

The terminal device 140 shown in this embodiment of this application mayexecute the technical solution of the timer processing method in anyembodiment shown in FIG. 2 to FIG. 4. Implementation principles andtechnical effects thereof are similar, and details are not describedherein again.

It should be understood that, the processor shown in FIG. 11 to FIG. 14may be a central processing unit (Central Processing Unit, CPU), and mayalso be another general-purpose processor, a digital signal processor(Digital Signal Processor, DSP), an application-specific integratedcircuit (Application Specific Integrated Circuit, ASIC), or the like.The general-purpose processor may be a microprocessor or the processormay be any conventional processor, or the like. The steps of the methodsdisclosed with reference to this application may be directly implementedby a hardware processor, or may be implemented by a combination ofhardware and a software module in a processor.

All or some of the steps in the foregoing method embodiments may beimplemented by a program instructing related hardware. The foregoingprogram may be stored in a computer-readable memory. When the program isexecuted, the steps of the method embodiments are performed. Theforegoing memory (storage medium) includes: a read-only memory(read-only memory, ROM), a RAM, a flash memory, a hard disk, a solidstate disk, a magnetic tape (magnetic tape), a floppy disk (floppydisk), an optical disc (optical disc), and any combination thereof.

An embodiment of this application further provides a computer-readablestorage medium. The computer-readable storage medium stores a computerprogram, and when executed by a processor, the computer program executesthe timer processing method shown in any one of the foregoingembodiments.

The computer-readable storage medium shown in this embodiment of thisapplication may execute the technical solution of the timer processingmethod in any embodiment shown in FIG. 2 to FIG. 4. Implementationprinciples and technical effects thereof are similar, and details arenot described herein again.

An embodiment of this application further provides a chip. The chipstores a computer program, and when executed by a processor, thecomputer program executes the timer processing method shown in any oneof the foregoing embodiments.

The chip shown in this embodiment of this application may execute thetechnical solution of the timer processing method in any embodimentshown in FIG. 2 to FIG. 4. Implementation principles and technicaleffects thereof are similar, and details are not described herein again.

All or some of the foregoing embodiments may be implemented throughsoftware, hardware, firmware, or any combination thereof. When softwareis used to implement the embodiments, the embodiments may be implementedcompletely or partially in a form of a computer program product. Thecomputer program product includes one or more computer instructions.When the computer program instructions are loaded and executed on acomputer, the procedures or functions according to the embodiments ofthis application are all or partially generated. The computer may be ageneral-purpose computer, a dedicated computer, a computer network, oranother programmable apparatus. The computer instructions may be storedin a computer-readable storage medium or may be transmitted from acomputer-readable storage medium to another computer-readable storagemedium. For example, the computer instructions may be transmitted from awebsite, computer, server, or data center to another website, computer,server, or data center in a wired (for example, a coaxial cable, anoptical fiber, or a digital subscriber line (Digital Subscriber Line,DSL)) or wireless (for example, infrared, radio, or microwave) manner.The computer-readable storage medium may be any usable medium accessibleby a computer, or a data storage device, such as a server or a datacenter, integrating one or more usable media. The usable medium may be amagnetic medium (for example, a floppy disk, a hard disk, or a magnetictape), an optical medium (for example, a DVD), a semiconductor medium(for example, a solid state disk (solid state Disk, SSD)), or the like.

A person skilled in the art should be aware that in the foregoing one ormore examples, functions described in the embodiments of thisapplication may be implemented by hardware, software, firmware, or anycombination thereof. When this application is implemented by software,these functions may be stored in a computer-readable medium ortransmitted as one or more instructions or code in the computer-readablemedium. The computer-readable medium includes a computer storage mediumand a communications medium, wherein the communications medium includesany medium that enables a computer program to be transmitted from oneplace to another. The storage medium may be any available mediumaccessible to a general-purpose or dedicated computer.

What is claimed is: 1-81. (canceled)
 82. A timer processing method,performed by a terminal device, the timer processing method comprising:receiving a first message from a network device, wherein the firstmessage is used to indicate a downlink assignment or an uplink grant andis scrambled using a first scrambling identifier; and in response to thereceiving of the first message scrambled by using the first scramblingidentifier, starting or restarting a timer, wherein the active downlinkBWP of the terminal device is not a default downlink BWP; and inresponse to the timer expiring, switching the active downlink BWP to thedefault downlink BWP.
 83. The method according to claim 82, wherein thefirst scrambling identifier is a cell radio network temporary identifier(C-RNTI) or a configured scheduling radio network temporary identifier(CS-RNTI).
 84. The method according to claim 82, wherein the methodfurther comprises: initiating a random access procedure; and stoppingthe timer in response to the initiating of the random access procedure.85. The method according to claim 82, wherein the first messagecomprises a carrier index, wherein the carrier index indicates a firstcarrier or a first serving cell.
 86. The method according to claim 85,wherein the active downlink BWP of the terminal device is a downlink BWPof the first carrier or the first serving cell indicated by the carrierindex, and the starting or restarting the timer, comprises: starting orrestarting a timer associated with the first carrier or the firstserving cell.
 87. The method according to claim 85, wherein the activedownlink BWP of the terminal device is a downlink BWP of a secondcarrier or a second serving cell used for receiving the first message,and the first carrier is different from the second carrier, or the firstserving cell is different from the second serving cell, and the startingor restarting the timer, comprises: starting or restarting a timer ofthe second carrier or the second serving cell used for receiving thefirst message.
 88. The method according to claim 85, wherein the timeris-associated with the active downlink BWP of the terminal device. 89.The method according to-claim 82, wherein the default downlink BWP isconfigured by the network device; or in a case that a default downlinkBWP is not configured for the terminal device, the default downlink BWPis an initial downlink BWP.
 90. The method according to claim 82,wherein the first message is carried on a physical downlink controlchannel (PDCCH).
 91. The method according to claim 84, wherein duringthe random access procedure, the timer is in a not-running state.
 92. Aterminal device, comprising a processor and a memory, wherein the memorystores one or more instructions or programs, the processor is coupled tothe memory, and the processor runs the one or more instructions orprograms, so that the terminal device executes the following steps:receiving a first message from a network device, wherein the firstmessage is used to indicate a downlink assignment or an uplink grant andis scrambled by using a first scrambling identifier; and in response tothe receiving of the first message scrambled by using the firstscrambling identifier, starting or restarting a timer, wherein theactive downlink BWP of the terminal device is not a default downlinkBWP; and in response to the timer expiring, switching the activedownlink BWP to the default downlink BWP.
 93. The terminal deviceaccording to claim 92, wherein the first scrambling identifier is a cellradio network temporary identifier (C-RNTI) or a configured schedulingradio network temporary identifier (CS-RNTI).
 94. The terminal deviceaccording to-claim 92, wherein the processor runs the one or moreinstructions or programs, so that the terminal device further executesthe following step: initiating a random access procedure; and stoppingthe timer in response to the initiating of the random access procedure.95. The terminal device according to claim 92, wherein the first messagecomprises a carrier index, wherein the carrier index indicates a firstcarrier or a first serving cell.
 96. The terminal device according toclaim 95, wherein the active downlink BWP of the terminal device is adownlink BWP of the first carrier or the first serving cell indicated bythe carrier index, and the starting or restarting the timer comprises:starting or restarting a timer associated with the first carrier or thefirst serving cell.
 97. The terminal device according to claim 95,wherein the active downlink BWP of the terminal device is a downlink BWPof a second carrier or a second serving cell used for receiving thefirst message, and the first carrier is different from the secondcarrier, or the first serving cell is different from the second servingcell, and the starting or restarting the timer, comprises: starting orrestarting a timer of the second carrier or the second serving cell usedfor receiving the first message.
 98. The terminal device according toclaim 95, wherein the timer is a timer associated with the activedownlink BWP of the terminal device.
 99. The terminal device accordingto claim 92, wherein the default downlink BWP is configured by thenetwork device; or in a case that a default downlink BWP is notconfigured for the terminal device, the default downlink BWP is aninitial downlink BWP.
 100. A computer-readable storage medium, whereinthe computer-readable storage medium stores a computer program, and whenexecuted by a processor, the computer program executes the methodaccording the following steps: receiving a first message from a networkdevice, wherein the first message is used to indicate a downlinkassignment or an uplink grant and is scrambled by using a firstscrambling identifier; and in response to the receiving of the firstmessage scrambled by using the first scrambling identifier, starting orrestarting a timer, wherein the active downlink BWP of the terminaldevice is not a default downlink BWP; and in response to the timerexpiring, switching the active downlink BWP to the default downlink BWP.101. The computer-readable storage medium according to claim 100,wherein the first scrambling identifier is a cell radio networktemporary identifier (C-RNTI) or a configured scheduling radio networktemporary identifier (CS-RNTI).